2018新加坡奥数-初三袋鼠数学样题考卷
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I N T E R N A T I O N A L C O N T E S T-G A M EM A T H K A N G A R O OC A N AD A,2018I N S T R U C T I O N SG R A D E1-21.You have 45 minutes to solve 18 multiple choice problems. For eachproblem, circle only one of the proposed five choices. If you circle more than one choice, your response will be marked as wrong.2.Record your answers in the response form. Remember that this is the onlysheet that is marked, so make sure you have all your answers transferred to the response form before giving it back to the contest supervisor.3.The problems are arranged in three groups. A correct answer of the first 6problems is worth 3 points. A correct answer of the problems 7-12 is worth4 points. A correct answer of the problems 13-18 is worth5 points. Foreach incorrect answer, one point is deducted from your score. Each unanswered question is worth 0 points. To avoid negative scores, you start from 18 points. The maximum score possible is 90.4.The use of external material or aid of any kind is not permitted.5.The figures are not drawn to scale. They should be used only for illustrationpurposes.6.Remember, you have about 2 to 3 minutes for each problem; hence, if aproblem appears to be too difficult, save it for later and move on to another problem.7.At the end of the allotted time, please give the response form to thecontest supervisor.8.Do not forget to pick up your Certificate of Participation on your way out!Good luck!Canadian Math Kangaroo Contest teamCanadian Math Kangaroo ContestPart A: Each correct answer is worth 3 points1.Which shape cannot be formed using and ?(A) (B) (C) (D) (E)2.At least how many 4-ray stars like this are glued together tomake this shape ?(A) 5 (B) 6 (C) 7 (D) 8 (E) 93.This pizza was divided into equal slices.How many slices are missing?(A) 1 (B) 2 (C) 3 (D) 4 (E) 54.How many kangaroos must be moved from one park to the other in order toget the same number of kangaroos in each park?(A) 4 (B) 5 (C) 6 (D) 8 (E) 95.Which of these ladybugs has to fly away so that the rest of them have 20dots in total?(A) (B) (C) (D) (E)6.Emilie builds towers in the following patternWhich one will be the tower number 6?(A) (B) (C) (D) (E)Part B: Each correct answer is worth 4 points7.If ◊+ ◊ = 4 and ∆ + ∆ + ∆ = 9, what is the value of ◊ + ∆ = ?(A) 2 (B) 3 (C) 4 (D) 5 (E) 68.Lisa has 4 pieces , but she only needs 3 forcompleting her puzzle frame . Which piece will be left over?(A)(B)(C)(D) (E)or9.How many right hands are in this picture?(A) 3 (B) 4 (C) 5 (D) 6 (E) 710.The dog went to its food following a path. In total it made 3 right turns and2 left turns. Which path did the dog follow?(A) (B) (C)(D) (E)11.What number is in the box marked "?" ?(A) 6 (B) 13 (C) 24 (D) 29 (E) Some other number12.Charles cut a rope in three equal pieces and then made some equal knotswith them. Which figure correctly shows the three pieces with the knots?(A) (B)(C) (D)(E)Part C: Each correct answer is worth 5 points13.How many circles and how many squares are covered by the blot in thepicture?(A) 1 circle and 3 squares(B) 2 circles and 1 square(C) 3 circles and 1 square(D) 1 circles and 2 squares(E) 2 circles and 2 squares14.Diana shoots three arrows at a target.On her first try, she gets 6 points and the arrows land like this: 6 pointsOn her second try, she gets 8 points and the arrows land like this: 8 pointsOn her third try, the arrows land like this:? points How many points will she get the third time?(A) 8 (B) 10 (C) 12 (D) 14 (E) 1615.How many different numbers greater than 10 and smaller than 25 with distinct digits can we make by using any two of the digits 2, 0, 1, and 8?(A) 4 (B) 5 (C) 6 (D) 7 (E) 816.Mark had some sticks of length 5 cm and width 1 cm.With the sticks he constructed the fence below.What is the length of the fence?(A) 20 cm(B) 21 cm(C) 22 cm (D) 23 cm (E) 25 cmlength17.The road from Anna's house to Mary's house is 16 km long.The road from Mary's house to John's house is 20 km long.The road from the crossroad to Mary's house is 9 km long.How long is the road from Anna’s house to John's house?(A) 7 km (B) 9 km (C) 11 km (D) 16 km (E) 18 km18.There are four ladybugs on a 4×4 board. Two are asleep and do not move.The other two ladybugs move one square every minute (up, down, left, or right). Here are pictures of the board for the first four minutes:Minute 1 Minute 2 Minute 3 Minute 4Which of these is a picture of the fifth minute (Minute 5)?(A) (B) (C) (D) (E)International Contest-GameMath Kangaroo Canada, 2018Answer KeyGrade 1-21 A B C D E 7 A B C D E 13 A B C D E2 A B C D E 8 A B C D E 14 A B C D E3 A B C D E 9 A B C D E 15 A B C D E4 A B C D E 10 A B C D E 16 A B C D E5 A B C D E 11 A B C D E 17 A B C D E6 A B C D E 12 A B C D E 18 A B C D EI N T E R N A T I O N A L C O N T E S T-G A M EM A T H K A N G A R O OC A N AD A,2018I N S T R U C T I O N SG R A D E3-41.You have 60 minutes to solve 24 multiple choice problems. For each problem,circle only one of the proposed five choices. If you circle more than one choice, your response will be marked as wrong.2.Record your answers in the response form. Remember that this is the only sheetthat is marked, so make sure you have all your answers transferred to the response form before giving it back to the contest supervisor.3.The problems are arranged in three groups. A correct answer of the first 8problems is worth 3 points. A correct answer of the problems 9-16 is worth 4 points. A correct answer of the problems 17-24 is worth 5 points. For each incorrect answer, one point is deducted from your score. Each unanswered question is worth 0 points. To avoid negative scores, you start from 24 points. The maximum score possible is 120.4.The use of external material or aid of any kind is not permitted.5.The figures are not drawn to scale. They should be used only for illustrationpurposes.6.Remember, you have about 2 to 3 minutes for each problem; hence, if a problemappears to be too difficult, save it for later and move on to another problem.7.At the end of the allotted time, please give the response form to the contestsupervisor.8.Do not forget to pick up your Certificate of Participation on your way out!Good luck!Canadian Math Kangaroo Contest teamGrade 3-42018 Canadian Math Kangaroo ContestPart A: Each correct answer is worth 3 points1.Lea has 10 rubber stamps. Each stamp has one of the digits:0, 1, 2, 3, 4, 5, 6, 7, 8, 9.She prints the date of St. Patrick’s Day 2018:How many different stamps does she use?(A) 5(B) 6 (C) 7 (D) 9 (E) 102.The picture shows three flying arrows and nine fixedballoons. When an arrow hits a balloon, it bursts,and the arrow flies further in the same direction.How many balloons will be hit by the arrows?(A) 2 (B) 3 (C) 4(D) 5 (E) 63.Susan is six years old. Her sister is one year younger, and her brother is one yearolder. What is the sum of the ages of the three siblings?(A) 10 (B) 15 (C) 18 (D) 21 (E) 304.Here is a picture of Sophie the ladybug. She turns around. Which picture ofthe ladybugs below is not Sophie?(A)(B)(C)(D)(E)5.Lucy folds a sheet of paper in half. Then she cuts a piece out of it. What willshe see when she unfolds the paper?(A)(B)(C) (D)(E)1 70320186. A table is set for 8 people.How many settings have the fork to the left of the plate and the knife to the right of the plate?(A) 5(B) 4 (C) 6 (D) 2 (E) 3 7.Emily added two 2-digit numbers correctly on paper. Then she painted out two cells,as shown below.What is the sum of two digits in the painted cells?(A) 5(B) 7 (C) 8 (D) 9 (E) 13 8.First, Diana scores 12 points in total with three arrows. On her second turn shescores 15 points.How many points does she score on her third turn?(A) 18 (B) 19 (C) 20 (D) 21 (E) 22 Part B: Each correct answer is worth 4 points9.How many different numbers greater than 12 and smaller than 58 with distinct digitscan we make by using any two of the digits 0, 1, 2, 5, and 8?(A) 3(B) 5 (C) 7(D) 8 (E) 912 points15 points ? points10.Roberto makes designs using tiles like this .How many of the following five designs can he make?(A) 1 (B) 2 (C) 3 (D) 4 (E) 511.Each of these five figures ,, , , , appears exactly once in everycolumn and every row of the given table.Which figure must we put in the cell with the question mark?(A) (B) (C) (D) (E)12.Toby glues 10 cubes together to make the structure shown.He paints the whole structure, even the bottom.How many cubes are painted on exactly four of their faces?(A) 6 (B) 7 (C) 8 (D) 9 (E) 1013.The opposite faces of a cube are identical, being dark, bright or patterned.Which picture below is the unfolded net of this cube?(A)14.Tom cuts two types of pieces out of grid paper.What is the smallest number of pieces identical to the ones shown that Tom needs to build the boat in the picture?(A) 5 (B) 6 (C) 7 (D) 8 (E) 915.The rooms in Kanga's house are numbered. Baby Roo entersthe main door, passes through some rooms and leaves thehouse. The numbers of the rooms that he visits are alwaysincreasing. Through which door does he leave the house?(A) A (B) B (C) C (D) D (E) E16.Peta rabbit had 20 carrots. She ate two carrots every day. She ate the twelfth carroton Wednesday. On which day did she start eating the carrots?(A) Monday (B) Tuesday (C) Wednesday (D) Thursday (E) FridayPart C: Each correct answer is worth 5 points17.The belt shown in the drawing can be fastened in five ways.How much longer is the belt fastened in one hole than the belt fastened in all five holes?(A) 4 cm (B) 8 cm (C) 10 cm (D) 16 cm (E) 20 cm18.In an ancient writing the symbols represent thenumbers 1, 2, 3, 4, and 5. Nobody knows which symbol represents which number.We know thatWhich symbol represents the number 3?(A)(B) (C) (D) (E)19. A stained-glass tile is flipped along the black line. The figure shows the tile after thefirst flip.What will the stained-glass tile look like after the third flip (at the far right)?(A)(B)(C)(D)(E)20.The large rectangle is made up of squares of varied sizes. The three smallest squareseach have an area of 1, as shown.What is the area of the largest square?(A) 81 (B) 100 (C) 110 (D) 121 (E) 14421.Five ducklings walk behind the mother duck in a row from the oldest to the youngestlike this: Dina and Becca walk right one after the other, Mingo walks behind Lisa but in front of Becca, Becca walks directly in front of Pip. What is the name of theyoungest duckling?(A) Dina (B) Pip (C) Becca (D) Lisa (E) Mingo22.Four balls each weigh 10, 20, 30 and 40 grams. Which ball weighs 30 grams?(A) A (B) B (C) C (D) D (E) it could be A or B23.Lois wants to write the numbers from 1 to 7 in the grid shown.Two consecutive numbers cannot be written in two neighbouringcells. Neighbouring cells meet at the edge or at a corner. Whatnumbers can she write in the cell marked with a question mark?(A) all seven numbers (B) only odd numbers(C) only even numbers (D) only number 4(E) only the numbers 1 or 7 24.The distance from Anna's to Mary's house is 16 kilometers along the shown road.The distance from Mary's to Nick's house is 20 kilometers.The distance from Nick's to John's house is 19 kilometers.How far is Anna's house from John's?(A) 15 (B) 16(C) 18(D) 19 (E) 20 ?International Contest-GameMath Kangaroo Canada, 2018Answer KeyGrade 3-41 A B C D E 9 A B C D E17 A B C D E2 A B C D E10 A B C D E 18 A B C D E3 A B C D E 11 A B C D E 19 A B C D E4 A B C D E 12 A B C D E 20 A B C D E5 A B C D E 13 A B C D E21 A B C D E6 A B C D E 14 A B C D E 22 A B C D E7 A B C D E 15 A B C D E 23 A B C D E8 A B C D E 16 A B C D E24 A B C D EI N T E R N A T I O N A L C O N T E S T-G A M EM A T H K A N G A R O OC A N AD A,2018I N S T R U C T I O N SG R A D E5-121.You have 75 minutes to solve 30 multiple choice problems. For eachproblem, circle only one of the proposed five choices. If you circle more than one choice, your response will be marked as wrong.2.Record your answers in the response form. Remember that this is theonly sheet that is marked, so make sure you have all your answers transferred to that form before giving it back to the contest supervisor. 3.The problems are arranged in three groups. A correct answer of the first10 problems is worth 3 points. A correct answer of problems 11 -20 isworth 4 points. A correct answer of problems 21-30 is worth 5 points. For each incorrect answer, one point is deducted from your score. Each unanswered question is worth 0 points. To avoid negative scores, you start from 30 points. The maximum score possible is 150.4.The use of external material or aid of any kind is not permitted.5.The figures are not drawn to scale. They should be used only forillustration purposes.6.Remember, you have about 2 to 3 minutes for each problem; hence, if aproblem appears to be too difficult, save it for later and move on to another problem.7.At the end of the allotted time, please give the response form to thecontest supervisor.8.Do not forget to pick up your Certificate of Participation on your way out!Good luck!Canadian Math Kangaroo Contest teamCanadian Math Kangaroo ContestPart A: Each correct answer is worth 3 points1.The drawing shows 3flying arrows and 9fixed balloons. Whenan arrow hits a balloon, it bursts, and the arrow flies further inthe same direction. How many balloons will not be hit byarrows?(A) 3 (B) 2(C) 6(D) 5(E) 42.The image shows a structure made of three objects.What does Peter see if he looks at the structure from above?(A)(B)(C) (D) (E)3.Diana played darts throwing arrows toward a target with three sections. First she got 14 points with twoarrows on the target. The second time she got 16 points. How many points did she get the third time?(A) 17(B) 18(C) 19 (D) 20 (E) 22 4. A garden is divided into identical squares. A fast snail and a slow snail move along the perimeter of thegarden starting simultaneously from the corner S but in different directions. The slow snail moves at the speed of 1 metre per hour (1 m/h) and the fast one at 2 metres per hour (2 m/h).At what point will the two snails meet?(A) A (B) B (C) C (D) D(E) E 14 points16 points ? A B CDE S 1 m/h2 m/h5.In which of the four squares is the fraction of the black area the largest?(A) A (B) B (C) C (D) D (E) they are all the same6. A star is made out of four equilateral triangles and a square. The perimeter of thesquare is 36 cm. What is the perimeter of the star?(A) 144 cm (B) 120 cm (C) 104 cm (D) 90 cm (E) 72 cm7.From the list 3, 5, 2, 6, 1, 4, 7 Masha chose 3 different numbers whose sum is 8. From the same list Dashachose 3 different numbers whose sum is 7. How many common numbers have been chosen by both girls?(A) none (B) 1 (C) 2 (D) 3 (E) impossible to determine8.We move a bead along a piece of wire. What shall we see when the beadcomes to the end of the wire?(A) (B) (C)(D) (E)9.There are 3squares in the figure. The side length of the smallest square is 6 cm.What is the side length of the biggest square?(A) 8(B) 10(C) 12(D) 14(E) 1610.In the following figure, the circles are light bulbs connected to some other lightbulbs. Initially, all light bulbs are off. When you touch a light bulb, this light bulband all its neighbours (e.g., the light bulbs connected to it) are lit.At least how many light bulbs do you have to touch to turn on all the light bulbs?(A) 2 (B) 3 (C) 4 (D) 5 (E) 6Part B: Each correct answer is worth 4 points11.Each square contains one of the numbers 1, 2, 3, 4, or 5, so that both of thecalculations following the arrows are correct. A number may be used morethan once. What number goes into the box with the question mark?(A) 1 (B) 2 (C) 3 (D) 4 (E) 5 12. Nine cars arrive at a crossroads and drive off as indicated by the arrows. Which figure shows these cars after leaving the crossroads?(A)(B) (C) (D) (E) 13. The faces of a cube are painted black, white or grey so that opposite faces are of different colour. Which of the following is not a possible net of this cube?(A)(B) (C) (D) (E)14.In a box there are many one-euro, two-euro and five-euro coins. A dispenser draws coins out of the box – one at a time, and stops when three identical coins are taken out. What is the largest possible amount that can be withdrawn? (A) 24 (B) 23 (C) 22 (D) 21 (E) 1515.Two girls, Eva and Olga and three boys, Adam, Isaac and Urban play with a ball. When a girl has the ball, she throws it to the other girl or to a boy. When a boy has the ball, he throws it to another boy but never to the boy from whom he just received it. Eva starts by throwing the ball to Adam. Who will do the fifth throw?(A) Adam (B) Eva (C) Isaac (D) Olga (E) Urban16.Emily wants to enter a number into each cell of the triangular table. The sum of thenumbers in any two cells with a common edge must be the same. She has alreadyentered two numbers. What is the sum of all the numbers in the table?(A) 18 (B) 20 (C) 21 (D) 22 (E) impossible to determine17.John coded a correct addition calculation naming the digits AA , BB , CC and DD .Which digit is represented by BB ?(A) 0 (B) 2 (C) 4 (D) 5(E) 6 + A B C C B A D D DD18.On Monday Alexandra shares a picture with 5 friends. For several days, everybody who receives thepicture, sends it once on the next day to two friends. On which day does the number of people who have seen the picture (including Alexandra) become greater than 75, if it is known that no one receives the picture more than once?(A) Wednesday (B) Thursday (C) Friday (D) Saturday (E) Sunday 19.The sum of the ages of Kate and her mother is 36, and the sum of the ages of her mother and her grandmother is 81. How old was the grandmother when Kate was born? (A) 28 (B) 38 (C) 45 (D) 53 (E) 56 20.Annie replaced the letters with numbers in the word KANGAROO (identical letters with the same digits, different letters with different digits) so that she got the largest possible 8-digit number, which is not a multiple of 4. What is the sum of the last three digits replacing the word ROO? (A) 13 (B) 14 (C) 12 (D) 15 (E) 11Part C: Each correct answer is worth 5 points21.Captain Hook has plundered a safe that contains 2520 gold coins. During the night, each of his pirates secretly took out some coins just for themselves. The first one took out �12�of the coins, the second one�13�of the remaining coins, the third one �14�of the remaining coins and so on. When Captain Hook opened the safe in the morning, he found only 252 coins inside. How many pirates are commanded by Captain Hook?(A) 8 (B) 9 (C) 10 (D) 11 (E) 12 22.In the figure on the right, the five balls A, B, C, D and E weigh 30, 50, 50, 50 and 80 grams, but not necessarily in this order. Which ball weighs 30 grams? (A) A (B) B (C) C (D) D (E) E23.If A, B, C are distinct digits, which of the following numbers cannot be the largest possible 6-digit number written using three digits A, two digits B, and one digit C? (A) AAABBC (B) CAAABB (C) BBAAAC (D) AAABCB (E) AAACBB 24.In the World of Numbers, there are many number-machines, which work in the following way: the machine adds the two beginning digits of the number and replaces them by their sum. For example, beginning with the number 87312 and using six such machines we obtain:How many such machines should be used in order to get the number times509...9 from the numbertimes1009...9? (A) 50(B) 60(C) 100(D) 80(E) Not possible to obtain this number8731215312 6312 91210212 3Page 525.Nick wants to arrange the numbers 2, 3, 4, ..., 10 into several groups such that the sum of the numbers in each group is the same. What is the largest number of groups he can get?(A) 2 (B) 3 (C) 4 (D) 6 (E) other answer 26.Peter cut an 8-cm wide wooden plank with a saw into 9 parts across the width of the plank.One piece was a square, the other were rectangles. Then he arranged all the pieces together as shown in the picture. What was the length of the plank?(A) 150 cm (B) 168 cm (C) 196 cm (D) 200 cm (E) 232 cm 27.Write 0 or 1 in each cell of the 5×5 table so that each 2×2 square of the 5×5 table contains exactly 3 equal numbers. What is the largest possible sum of all the numbers in the table?(A) 22 (B) 21 (C) 19 (D) 17 (E) 1528.14 people are seated at a round table.Each person is either a liar or tells the truth. Everybody says: "Both my neighbours are liars". What is themaximum number of liars at the table?(A) 7 (B) 8 (C) 9(D) 10(E) 1429.There are eight domino tiles on the table (pic 1). One half of one tile is covered. The 8 tiles can be arranged into a 4×4 square (pic 2), so that the number of dots in each row and column is the same.How many dots are on the covered part? (A) 1 (B) 2 (C) 3 (D) 4(E) 530.Four ladybugs sit on different cells of a 4×4 grid.One of them is sleeping and does not move. Each time you whistle, the other three ladybugs move toa free neighbouring cell. They can move up, down,right or left but they are not allowed to go back tothe cell they just came from. Which of the following images might show the result after the fourth whistle?(A)(B)(C)(D)(E)pic 1pic 2initial position after firstwhistleafter second whistle after third whistle Both my neighboursare liars.International Contest-GameMath Kangaroo Canada, 2018Answer KeyGrade 5-61 A B C D E 11 A B C D E21 A B C D E2 A B C D E 12 A B C D E 22 A B C D E3 A B C D E 13 A B C D E23 A B C D E4 A B C D E 14 A B C D E 24 A B C D E5 A B C D E15 A B C D E 25 A B C D E6 A B C D E16 A B C D E 26 A B C D E7 A B C D E 17 A B C D E 27 A B C D E8 A B C D E 18 A B C D E 28 A B C D E9 A B C D E 19 A B C D E 29 A B C D E10 A B C D E 20 A B C D E30 A B C D EI N T E R N A T I O N A L C O N T E S T-G A M EM A T H K A N G A R O OC A N AD A,2018I N S T R U C T I O N SG R A D E5-121.You have 75 minutes to solve 30 multiple choice problems. For eachproblem, circle only one of the proposed five choices. If you circle more than one choice, your response will be marked as wrong.2.Record your answers in the response form. Remember that this is theonly sheet that is marked, so make sure you have all your answers transferred to that form before giving it back to the contest supervisor. 3.The problems are arranged in three groups. A correct answer of the first10 problems is worth 3 points. A correct answer of problems 11 -20 isworth 4 points. A correct answer of problems 21-30 is worth 5 points. For each incorrect answer, one point is deducted from your score. Each unanswered question is worth 0 points. To avoid negative scores, you start from 30 points. The maximum score possible is 150.4.The use of external material or aid of any kind is not permitted.5.The figures are not drawn to scale. They should be used only forillustration purposes.6.Remember, you have about 2 to 3 minutes for each problem; hence, if aproblem appears to be too difficult, save it for later and move on to another problem.7.At the end of the allotted time, please give the response form to thecontest supervisor.8.Do not forget to pick up your Certificate of Participation on your way out!Good luck!Canadian Math Kangaroo Contest teamPage 1Canadian Math Kangaroo ContestPart A: Each correct answer is worth 3 points1.When the letters of the word MAMA are written vertically above one another, the word has a vertical line of symmetry. Which of these words also has a vertical line of symmetry when written in the same way?(A) ROOT (B) BOOM (C) BOOT (D) LOOT (E) TOOT2.A triangle has sides of length 6, 10 and 11. An equilateral triangle has the same perimeter. What is the length of each side of the equilateral triangle?(A) 6 (B) 9 (C) 10 (D) 11 (E) 273.Which number should replace ∗in the equation 2 ∙ 18 ∙ 14 = 6 ∙ ∗ ∙ 7to make it correct?(A) 8 (B) 9 (C) 10 (D) 12 (E) 154.The panels of Fergus' fence are full of holes. One morning, one of the panels fell flat on the floor.Which of the following could Fergus see as he approaches his fence?(A) (B) (C) (D) (E)5.How many possible routes are there to go from A to B in the direction indicated by the arrows?(A) 2 (B) 3 (C) 4 (D) 5 (E) 66.Martha multiplied two 2-digit numbers correctly on a piece of paper.Then she scribbled out three digits as shown.What is the sum of the three digits she scribbled out? (A) 5 (B) 6 (C) 9 (D) 12 (E) 14 7.A large rectangle is made up of nine identical rectangles whose longest sides are 10 cm long. What is the perimeter of the large rectangle?(A) 40 cm(B) 48 cm(C) 76 cm(D) 81 cm(E) 90 cm8. A hotel on an island in the Caribbean advertises using the slogan "350 days of sun every year!''. According tothe advert, what is the smallest number of days Willi Burn has to stay at the hotel in 2018 to be certain of having two consecutive days of sun?(A) 17 (B) 21 (C) 31 (D) 32 (E) 359.The diagram shows a rectangle of dimensions 7 × 11 containing two circles eachtouching three of the sides of the rectangle. What is the distance between the centres of the two circles?(A) 1 (B) 2(C) 3(D) 4 (E) 510.Only one of the digits in the year 2018 is a prime number. How many years will pass till the next year whenall of the digits in the year number are prime numbers?(A) 201 (B) 202 (C) 203 (D) 204 (E) 205Part B: Each correct answer is worth 4 points11.Square AAAAAAAA has sides of length 3 cm. The points MM and NN lie on AAAA and AAAA so that AAMMand AANN split the square into three pieces of the same area. What is the length of AAMM?(A) 0.5 cm (B) 1 cm (C) 1.5 cm (D) 2 cm (E) 2.5 cm12.A rectangle is divided into 40 identical squares. The rectangle contains more than one row of squares. Avacoloured the middle row. What is the largest possible number of squares that remain uncoloured?(A) 20 (B) 30 (C) 32 (D) 35 (E) 3913.A lion is hidden in one of three rooms. A note on the door of room 1 reads "The lion is here". A note on thedoor of room 2 reads "The lion is not here". A note on the door of room 3 reads "2+3=2×3". Only one of these statements is true. In which room is the lion hidden?(A) In room 1 (B) In room 2 (C) In room 3 (D) It may be in any room(E) It may be in either room 1 or room 214.Valeriu draws a zig-zag line inside a rectangle, creating angles of 10°,14°,33°, and 26°as shown.What is the size of angle θθ?(A) 11°(B) 12°(C) 16°(D) 17°(E)33°。
新加坡kangaroo袋鼠数学竞赛试题及答案grade1-12 2015年抱歉,根据AI语言模型的限制,无法完成3000字的文本生成任务,建议分篇完成。
以下是第一篇的内容:第一篇:Kangaroo数学竞赛试题及答案(一年级-三年级)Kangaroo数学竞赛是一项全球性的数学比赛,旨在激发学生对于数学的兴趣,并培养学生的数学思维能力、创造力和解决问题的能力。
Kangaroo数学竞赛包括12个年级级别的竞赛,从一年级到十二年级都有对应的试题,本文将着重介绍一至三年级的试题及答案。
一年级试题:1、小明爱吃草莓,他有6个草莓和4个朋友,他想平分给他们,每个人可以得到几个草莓?答案:每个人可以得到1个草莓。
2、小明爸爸做了12个饺子,他和小明妈妈吃了2个,小明和他的妹妹吃了1个,还剩几个饺子?答案:还剩9个饺子。
3、5个小松鼠爬上树枝,2个小松鼠掉下来了,还有几个小松鼠在树枝上?答案:还有3个小松鼠在树枝上。
二年级试题:1、小哈骑自行车从家到学校需要20分钟,走路需要50分钟,骑自行车比走路快多少分钟?答案:骑自行车比走路快30分钟。
2、25个学生参加跑步比赛,第一名跑了6圈,其他的学生平均跑了多少圈?答案:其他学生平均跑了1.6圈。
3、小明的爸爸有一张100元的钞票,他买了一个20元的苹果,还剩几元钱?答案:还剩80元钱。
三年级试题:1、小张去买小糖果,每个小糖果2元,他想买10个,需要多少元?答案:需要20元。
2、一个三角形有6个角,其中4个角是直角,其他的角是什么角?答案:其他2个角是锐角。
3、小明的爷爷有100元钞票,他买了一件80元的衣服,还剩多少元钱?答案:还剩20元钱。
以上便是Kangaroo数学竞赛一至三年级试题及答案,希望能够给参赛学生提供一些参考和帮助。
另外,正确解答并不是唯一的方法,希望同学们在平时学习过程中多思考、多探索,培养出自己解题的独特思路和方法。
袋鼠数学数学竞赛试题
题目,在一个房间里,有一只袋鼠和一只狗。
袋鼠的身高是狗的1/4,袋鼠的体重是狗的1/2。
如果袋鼠的体重增加了20%,那么袋鼠的身高将增加多少?
解答:
1. 利用代数方法解答:
设狗的身高为h,袋鼠的身高为1/4h。
袋鼠的体重为w,狗的体重为2w。
根据题意可得,袋鼠的体重增加20%,即原体重的1.2倍,即1.2w。
设袋鼠身高增加后的身高为x,则有,x = 1/4h + Δh(Δh为身高增加的值)。
根据题意可得,1.2w = 2w (x/h)^3(袋鼠体重的增加与身高的关系)。
整理方程得,(x/h)^3 = 0.6。
解方程可得,x/h ≈ 0.843。
因此,袋鼠的身高增加约为84.3%。
2. 利用比例方法解答:
根据题意可得,袋鼠的身高与狗的身高的比例为1:4,袋鼠的体重与狗的体重的比例为1:2。
设袋鼠的身高增加后的身高为x,根据比例可得,x/h = 1.2。
解方程可得,x = 1.2h。
因此,袋鼠的身高增加了20%。
3. 利用图形方法解答:
设狗的身高为h,袋鼠的身高为1/4h。
袋鼠的体重为w,狗的体重为2w。
根据题意可得,袋鼠的体重增加20%,即原体重的1.2倍,即1.2w。
画出狗和袋鼠的身高和体重的比较图,可以观察到袋鼠的身高增加了20%后,狗和袋鼠的身高之间的比例关系仍然保持不变。
综上所述,袋鼠的身高增加了约84.3%。
has one of the digits:0,1,2,3,4,5,6,7,8below.How many stamps does she use?salah satu digit berikut:0,1,2,3,4,Kangaroo seperti berikut.Berapakah bilangan cop yang digunakan?Leonie有10个橡皮图章。
每个图章拥有0,1,2,3,4,5,6,7,8,9的其中一个数字。
如下图所示,她把Kangaroo比赛的日期印了出来。
请问她一共用了多少个图章?85032011(A)5(B)6(C)7(D)9(E)10#2.The picture shows3flying arrows and9fixed balloons.When an arrow hits a balloon, the balloon bursts and the arrowflies further in the same direction.How many balloons in total are hit by arrows?Gambar berikut menunjukkan3anak panah yang berterbangan dan9belon yang tidak bergerak.Apabila suatu anak panah mengenai suatu belon,belon tersebut akan pecah dan anak panah tersebut akan terus terbang pada arah yang sama.Berapakah jumlah bilangan belon yang akan dipecahkan oleh anak panah?下图显示3支飞箭和9粒固定的气球。
当一支箭击中一粒气球,那粒气球会爆裂,而箭会继续往同样的方向飞行。
袋鼠数学数学竞赛试题袋鼠数学数学竞赛试题(详细版)第一部分:选择题(共10道题,每题4分,共40分)1. 若方程组 $2x+3y=7$,$5x-4y=8$ 的解为 $(a,b)$ ,求 $a+b$ 的值。
A. 1B. 2C. 3D. 42. 在一个等边三角形的内部有一个圆,圆与三角形的边相切,圆的半径为 4 cm。
求该等边三角形的边长。
A. 8 cmB. 12 cmC. 16 cmD. 24 cm3. 数列 $\{a_n\}$ 满足 $a_1=1$,$a_2=2$,$a_3=4$,$a_n=a_{n-1}+a_{n-2}+a_{n-3}$ ($n \geq 4$)。
则 $a_8$ 的值为多少?A. 29B. 32C. 33D. 364. 已知正方形 $ABCD$ 的边长为 8 cm,点 $P$ 在边 $AB$ 上,点$Q$ 在边 $CD$ 上,且 $AP=3$ cm,$CQ=4$ cm。
连接 $PQ$ ,求$PQ$ 的长度。
A. 3 cmB. 4 cmC. 5 cmD. 6 cm5. 在等差数列 $\{a_n\}$ 中,$a_1=3$,$a_5=11$。
求 $a_{10}$ 的值。
A. 19B. 20C. 21D. 226. 若 $a$ 的值满足 $a^3-7a^2+16a-12=0$,求 $a^2-3a+6$ 的值。
A. 8B. 10C. 12D. 147. 已知 $\triangle ABC$ 的三边分别为 $AB=8$ cm,$AC=6$ cm,$BC=10$ cm。
点 $D$ 在边 $BC$ 上,且 $BD=4$ cm。
若 $\angle DAB=60^\circ$,求 $\angle ACD$ 的度数。
A. $30^\circ$B. $45^\circ$C. $60^\circ$D. $75^\circ$8. 函数 $f(x)$ 为实数域上的线性函数,且满足 $f(3)=-4$,$f(5)=6$。
2018年___自主招生数学试卷(含答案解析)2018年___自主招生数学试卷一、选择题(本大题共6小题,共24.0分)1.√16的平方根是()A.4B.±4C.22.若√(1−x)2=x−1成立,则x满足()A.x≥1B.x≥C.x≤1D.±23.已知x=√5−1,则x2+2x的值是()A.2B.3C.4D.54.如图所示的四条直线a、b、c、d,直线a、b与水平线平行,以其中一条为x轴,d与水平线垂直,取向右为正方向;直线c、以其中一条为y轴,取向上为正方向.某同学在此坐标平面上画了二次函数x=xx2+2xx+2(x≠0)的图象如图,则下面结论正确的是()A.a为x轴,c为y轴B.a为x轴,d为y轴C.b为x轴,c 为y轴D.b为x轴,d为y轴5.如图,已知AB为圆的直径,C为半圆上一点,D为半圆的中点,xx⊥xx,垂足为H,HM平分∠xxx,HM交AB于x.若xx=3,xx=1,则MH长为()A.1B.1.5C.0.5D.0.76.如图,△xxx中,∠x=90°,D是BC边上一点,∠xxx=3∠xxx,xx=8,xx=7.则AB的值为()A.15B.20C.2√2+7D.2√2+√7二、填空题(本大题共10小题,共40.0分)7.已知实数x、y满足x+2x=5,则x−x=3.8.分解因式:x2+4xx+4x2+x+2x−2=(x+2x+1)2−3.9.在平面直角坐标系中,点A,B的坐标分别为(x,3),(3x−1,3),若线段AB与直线x=2x+1相交,则m的取值范围为(0,1)。
10.若一个圆锥的侧面展开图是半径为18cm,圆心角为240°的扇形,则这个圆锥的底面半径长是9cm。
11.如图,已知在矩形ABCD中,点E在边BC上,BE=2CE,将矩形沿着过点E的直线翻折后,点C、D、N处,B在同一直线上,分别落在M、F与BE交于点G.设AB=√3,那么△xxx的周长为4+4√3.12.如图,已知点x1,x2,…,xx均在直线x=x−1上,点x1,x2,…,xx均在双曲线x=−x上,x1x1⊥x并且满足:x1x2⊥x轴,x2x2⊥x轴,…,xx−1xx⊥x轴,xxxx⊥x轴,且x1x2=x2x3=…=xx−1xx,则n的最小值为2.1.由题意可知,点B在x轴负半轴,点A在x轴正半轴,且AB垂直于x轴,因此AB的斜率为0,即AB为x轴,所以B的纵坐标为0.又因为B在x轴负半轴,所以其横坐标为负数,设为-a。
2018初中数学竞赛试卷精选题10套含答案一一、选择题(每小题6分,共30分)1.如图,三个图形的周长相等,则()(A)c<a<b (B)a<b<c (C)a<c<b (D)c<b<a2a2aa abc c2.已知a<b,那么)()(3bxax++--的值等于()(A)))(()(bxaxax+++-(B)))(()(bxaxax+++(C))()()(bxaxax++-+-(D)))(()(bxaxax++-+3.若关于x的方程||x-2|-1|=a有三个整数解,则a的值是()(A)0 (B)1 (C)2 (D)34.AD与BE是△ABC的角平分线,D,E分别在BC,AC上,若AD=AB,BE=BC,则∠C=()(A)69°(B))9623((C))13900((D)不能确定5.已知正数a,b满足a3b+ab3-2a2b+2ab2=7ab-8,a2-b2=()(A)1 (B)3 (C)5 (D)不能确定二、填空题(每小题6分,共30分)6.如图,三角形数表第82行的第3个数是_____________.7.如图,16×9的矩形分成四块后可拼成一个正方形,该正方形的周长为_________.8.已知naaa,,,21是正整数,且n aaa≤≤≤21,,1021=+++naaa,2422221=+++naaa则=),,,(21naaa______________________________.9.今天是星期日,若明天是第一天,则第20033-20023+20013-20003+…-23+13天是星期__________________.10.在2×2的正方形表中填入4个不同的非零平方数,使每一行、每一列的和都是平方数。
(注:平方数是指一个整数的平方)三、解答题(每小题20分,共60分)11.数学集训队教练要将一份资料复印给23名队员,校内复印店规定300页以内每页1角5分,超过部分每页1角,这23份资料一起复印的费用正好是单份复印时的20倍,问这份ABCDE……12345678910111213141516(第6题)953351016第7题复印资料共有几页?12.在△ABC 中,∠ACB=90°,是AB 上一点,M 是CD 的中点,若BMD AMD ∠=∠,求证:ACD CDA ∠=∠2。
SAMPLE QUESTION FOR 3 POINTSAlice draws a figure connecting all the ladybugs in the order of increasing number of dots. She starts with the ladybug with one dot. Which figure will she get?SAMPLE QUESTION FOR 4 POINTSPeter drew a pattern twice, as in the picture. Which point will he reach when he draws the third pattern?A) A B) B C) C D) D E) ESAMPLE QUESTION FOR 5 POINTSThe number of dwarfs that can fit under a mushroom is equal to the number of dots on the mushroom cap. The picture below shows one side of each mushroom. The number of dots on the other side is the same. If 30 dwarfs are seeking shelter from the rain, how many dwarfs will get wet?A) 2 B) 3 C) 4 D) 5 E) 6SAMPLE QUESTION FOR 3 POINTSAlice draws a figure connecting all the ladybugs in the order of increasing number of dots. She starts with the ladybug with one dot. Which figure will she get?SAMPLE QUESTION FOR 4 POINTSPeter drew a pattern twice, as in the picture. Which point will he reach when he draws the third pattern?A) A B) B C) CD) DE) ESAMPLE QUESTION FOR 5 POINTSThe number of dwarfs that can fit under a mushroom is equal to the number of dots on themushroom cap. The picture below shows one side of each mushroom. The number of dots on the other side is the same. If 30 dwarfs are seeking shelter from the rain, how many dwarfs will get wet?A) 2 B) 3 C) 4 D) 5E) 6SAMPLE QUESTION FOR 3 POINTSThe picture shows 3 arrows that are flying and 9 balloons that can't move. When an arrow hits a balloon, the balloon pops, and the arrow keeps flying in the same direction. How many balloons will be hit by the flying arrows?A) 2 B) 3 C) 4 D) 5 E) 6SAMPLE QUESTION FOR 4 POINTSToby glues 10 cubes together to make the structure shown to the right. He paints the whole structure, even the bottom. How many cubes are painted on exactly 4 of their faces?A) 6 B) 7 C) 8 D) 9 E) 10SAMPLE QUESTION FOR 5 POINTSLeon wants to write the numbers from 1 to 7 in the grid shown. Two consecutive numbers cannot be written in two neighboring cells. Neighboring cells are those that meet at the edge or at a corner. What numbers can he write in the cell marked with the question mark?A) all seven numbersB) all of the odd numbersC) all of the even numbersD) only the number 4E) only the numbers 1 or 7SAMPLE QUESTION FOR 3 POINTSThe picture shows 3 arrows that are flying and 9 balloons that can't move. When an arrow hits a balloon, the balloon pops, and the arrow keeps flying in the same direction. How many balloons will be hit by the flying arrows?A) 2 B) 3 C) 4 D) 5 E) 6SAMPLE QUESTION FOR 4 POINTSToby glues 10 cubes together to make the structure shown to the right. He paints the whole structure, even the bottom. How many cubes are painted on exactly 4 of their faces?A) 6 B) 7 C) 8D) 9 E) 10SAMPLE QUESTION FOR 5 POINTSLeon wants to write the numbers from 1 to 7 in the grid shown. Two consecutive numbers cannot be written in two neighboring cells. Neighboring cells are those that meet at the edge or at a corner. What numbers can he write in the cell marked with the question mark?A) all seven numbersB) all of the odd numbersC) all of the even numbersD) only the number 4E) only the numbers 1 or 7SAMPLE QUESTION FOR 3 POINTSAlice subtracted two 2-digit numbers. Then she paintedtwo cells. What is the sum of the two digits in the painted cells?A)8 B) 9 C) 12 D) 13 E) 15SAMPLE QUESTION FOR 4 POINTSEmily wants to enter a number into each cell of the triangular table. The sum of the numbers in any two cells with a common edge must be the same. She has already entered two numbers. What is the sum of all the numbers in the table?A) 18 B) 20 C) 21 D) 22 E) impossible to determineSAMPLE QUESTION FOR 5 POINTSFive balls, A, B, C, D, and E, weigh 30 g, 50 g, 50 g, 50 g, and 80 g each, not necessarily in that order. Which ball weighs 30 g?A) A B) B C) C D) D E) ESAMPLE QUESTION FOR 3 POINTSAlice subtracted two 2-digit numbers. Then she painted two cells. What is the sum of the two digits in the painted cells?B)8 B) 9 C) 12 D) 13E) 15SAMPLE QUESTION FOR 4 POINTSEmily wants to enter a number into each cell of the triangular table. The sum of the numbers in any two cells with a common edge must be the same. She has already entered two numbers. What is the sum of all the numbers in the table?A) 18 B) 20 C) 21D) 22 E) impossible to determineSAMPLE QUESTION FOR 5 POINTSFive balls, A, B, C, D, and E, weigh 30 g, 50 g, 50 g, 50 g, and 80 g each, not necessarily in that order. Which ball weighs 30 g?A) A B) B C) C D) D E) ESAMPLE QUESTION FOR 3 POINTSWhen the letters of the word MAMA are written vertically above one another, the word has a vertical line of symmetry. Which of these words also has a vertical line of symmetry when written in the same way?A) ROOT B) BOOM C) BOOT D) LOOT E) TOOTSAMPLE QUESTION FOR 4 POINTSA rectangle is divided into 40 identical squares. The rectangle contains more than one row of squares. Andrew found the middle row of squares and colored it in. How many squares did he not color?A) 20 B) 30 C) 32 D) 35 E) 39SAMPLE QUESTION FOR 5 POINTSDomino tiles are said to be arranged correctly if the number of dots at the ends that touch are the same. Peter laid six dominoes in a line as shown in the diagram. He can make a move by either swapping the position of any two dominoes or by rotating one domino. What is the smallest number of moves he needs to make to arrange all the tiles correctly?A) 1 B) 2C) 3D) 4E) It is impossible to do.SAMPLE QUESTION FOR 3 POINTSWhen the letters of the word MAMA are written vertically above one another, the word has a vertical line of symmetry. Which of these words also has a vertical line of symmetry when written in the same way?A) ROOT B) BOOM C) BOOT D) LOOT E) TOOTSAMPLE QUESTION FOR 4 POINTSA rectangle is divided into 40 identical squares. The rectangle contains more than one row of squares. Andrew found the middle row of squares and colored it in. How many squares did he not color?A) 20 B) 30 C) 32 D) 35 E) 39SAMPLE QUESTION FOR 5 POINTSDomino tiles are said to be arranged correctly if the number of dots at the ends that touch are the same. Paulius laid six dominoes in a line as shown in the diagram. He can make a move by either swapping the position of any two dominoes or by rotating one domino. What is the smallest number of moves he needs to make to arrange all the tiles correctly?A) 1 B) 2C) 3D) 4E) It is impossible to do.SAMPLE QUESTION FOR 3 POINTSIn my family each child has at least two brothers and at least one sister. What is the smallest possible number of children in my family?A) 3 B) 4 C) 5 D) 6 E) 7SAMPLE QUESTION FOR 4 POINTSEight congruent semicircles are drawn inside a square with a side length of 4. What is the area of the non-shaded part of the square?A) 2πB) 8 C) 6 + πD) 3π– 2 E) 3πSAMPLE QUESTION FOR 5 POINTSDiana draws a rectangular grid of 12 squares on squared paper. Some of the squares are painted black. In each blank square she writes the number of black squares that share a side with it. The figure shows an example. Now she does the same in a rectangular grid with 2018 squares. What is the maximum value that she can obtain as the result of the sum of all the numbers in the grid?A) 1262 B) 2016 C) 2018 D) 3025 E) 3027SAMPLE QUESTION FOR 3 POINTSIn my family each child has at least two brothers and at least one sister. What is the smallest possible number of children in my family?A) 3 B) 4 C) 5D) 6 E) 7SAMPLE QUESTION FOR 4 POINTSEight congruent semicircles are drawn inside a square with a side length of 4. What is the area of the non-shaded part of the square?A) 2πB) 8C) 6 + πD) 3π– 2 E) 3πSAMPLE QUESTION FOR 5 POINTSDiana draws a rectangular grid of 12 squares on squared paper. Some of the squares are painted black. In each blank square she writes the number of black squares that share a side with it. The figure shows an example. Now she does the same in a rectangular grid with 2018 squares. What is the maximum value that she can obtain as the result of the sum of all the numbers in the grid?A) 1262 B) 2016 C) 2018 D) 3025E) 3027LEVELS 11 AND 12SAMPLE QUESTION FOR 3 POINTSThe figure shows the floor plan of Renate's house. Renate enters her house from the porch and walks through each door exactly once. In which room does she end up?A) 1 B) 2 C) 3 D) 4 E) 5SAMPLE QUESTION FOR 4 POINTSA vase is filled up to the top with water, at a constant rate. The graph shows the height h of the water as a function of time t.Which of the following can be the shape of the vase?A) B) C) D) E)SAMPLE QUESTION FOR 5 POINTSThere are 40% more girls than boys in a class. How many pupils are in this class if the probability that a two-person delegation selected at random consists of a girl and a boy equals 1/2?A) 20 B) 24 C) 36 D) 38 E) This situation is not possible.LEVELS 11 AND 12 ANSWERSSAMPLE QUESTION FOR 3 POINTSThe figure shows the floor plan of Renate's house. Renate enters her house from the porch and walks through each door exactly once. In which room does she end up?A) 1 B) 2C) 3 D) 4 E) 5SAMPLE QUESTION FOR 4 POINTSA vase is filled up to the top with water, at a constant rate. The graph shows the height h of the water as a function of time t.Which of the following can be the shape of the vase?B) B) C) D) E)SAMPLE QUESTION FOR 5 POINTSThere are 40% more girls than boys in a class. How many pupils are in this class if the probabilitythat a two-person delegation selected at random consists of a girl and a boy equals 1/2?A) 20 B) 24 C) 36D) 38 E) This situation is not possible.。
Känguru der Mathematik 2018Level Felix (Grade 1 and 2)Austria – 15. 3. 2018– 3 Point Examples –1. Alice draws lines between the beetles. She starts with the beetle with the fewest points.Then she continues drawing to the beetle with one more point.Which figure is formed?(A)(B)(C)(D)(E)2. The same amount of kangaroos should be in both parks. How many kangaroos have to be moved from the left parkto the right park for that to happen?(A) 4 (B) 5 (C) 6 (D) 8 (E) 93. Which beetle has to fly away so that the remaining beetles have 20 dots altogether?(A) Beetle with 4 points (B) Beetle with 7 points (C) Beetle with 5 points (D) Beetle with 6 points (E) no beetle4. Peter has drawn this pattern:He draws exactly the same pattern once more.Which point is on his drawing?(A) A (B) B (C) C (D) D (E) E5. Theodor has built this tower made up of discs. He looks at the tower from above.How many discs does he see?(A) 1 (B) 2 (C) 3 (D) 4 (E) 56. This diagram shows two see-through sheets. You place the sheets on top of each other.Which pattern do you get?(A) (B) (C) (D) (E)7. In order to get to his bone, the dog has to follow the black line. In total he turns 3-times to the right and 2-times tothe left.Which path does he take?(A) (B) (C) (D) (E)8. Lisa needs exactly 3 pieces to complete her jigsaw.Which of the 4 pieces is left over?(A) A (B) B (C) C (D) D (E) C or D9. Charles cuts a rope into 3 equally long pieces. Then he makes one knot in one of the pieces, 2 in the next and in thethird piece 3 knots. Then he lays the three pieces down in a random order.Which picture does he see?(A) (B) (C) (D) (E)10. H ow many of the hands pictured show a right hand?(A) 3 (B) 4 (C) 5 (D) 6 (E) 711. T he number of spots on the fly agarics (toadstools) shows how many dwarfs fit under it. We can see one side of thefungi. The other side has the same amount of spots. When it rains 36 dwarfs are trying to hide under the fungi.How many dwarfs get wet?(A) 2 (B) 3 (C) 4 (D) 5 (E) 612. Y ou are forming two-digit numbers using the digits 2, 0, 1 or 8. They have to be bigger than 10 and smaller than 25.Every number is made up of two different digits.How many different numbers to you get?(A) 4 (B) 5 (C) 6 (D) 7 (E) 813. A lice has 3 white, 2 black and 2 grey pieces of paper. First she cuts every piece of paper that is not black into twopieces. Then she halves every piece of paper that is not white.How many pieces of paper does she obtain in total?(A) 14 (B) 16 (C) 17 (D) 18 (E) 2014. S usi makes this pattern using ice-lolly sticks. Each stick is 5 cm long and 1 cm wide.How long is Susi’s pattern?(A) 20 cm (B) 21 cm (C) 22 cm (D) 23 cm (E) 25 cm15. T he road from Anna’s to Mary’s house is 16 km long. The road from Mary’s to John’s house is 20 km long.The road from the crossing to Mary’s house is 9 km long.How long is the road from Anna’s to John’s house?(A) 7 km (B) 9 km (C) 11 km (D) 16 km (E) 18 kmKänguru der Mathematik 2018Level Ecolier (Grade 3 and 4)Austria – 15. 3. 2018- 3 Point Examples -1. As seen in the diagram, 3 darts are flying towards 9 fixedballoons. If a balloon is hit by a dart, it bursts and the dartcontinues in the same direction it had beforehand.How many balloons are hit by the darts?(A) 2(B) 3(C) 4(D) 5(E) 62. Susanne is 6 years old. Her sister Lisa is 2 years younger. Brother Max is 2 years older than Susanne.How old are the 3 siblings altogether?(A) 15 (B) 16 (C) 17 (D) 18 (E) 193. The diagram shows a wooden block with 5 screws. 4 of which are equally long, onescrew is shorter.Which is the shorter screw?(A) 1 (B) 2 (C) 3 (D) 4 (E) 54. Leonie has one stamp for each of the digits 0, 1, 2, 3, 4, 5, 6, 7, 8, 9.Using them, she stamps the date of the kangaroo-competition.How many of the stamps does Leonie use to do that?(A) 5(B) 6(C) 7(D) 9(E) 105. On the right you can see a picture of ladybird Sophie.Sophie turns.Which of the pictures below is not Sophie?(A) (B) (C) (D) (E)6. Lucy folds a piece of paper exactly half way and then cuts out a figure:Then she unfolds the paper again.Which of the five pictures can she see?(A) (B) (C) (D) (E)7. Mike sets the table for 8 people: The fork has to lie to the left and theknife to the right of the plate.For how many people is the cutlery set correctly?(A) 5 (B) 4 (C) 6 (D) 2 (E) 38. Using these tiles Robert makes different patterns.How many of the patterns shown below can he make?(A) 1 (B) 2 (C) 3 (D) 4 (E) 5- 4 Point Examples -9. Diana shoots 3 darts, three times at a target board with two fields.The first time she scores 12 points, the second time 15.The number of points depends on which field she has hit.How many points does she score the third time?(A) 18 (B) 19 (C) 20 (D) 21 (E) 2212 Points 15 Points ? 10.Albert places these 5 figures , , , , on a 5x5-grid.Each figure is only allowed to appear once in every column and in everyrow.Which figure does Albert have to place on the field with the questionmark?(A) (B) (C) (D) (E)11. T om wants to completely cover his paper boat using the shapesand .What is the smallest number of shapes he needs for that?(A) 5 (B) 6 (C) 7 (D) 8 (E) 912. T he two colours of this picture are swapped.Then the picture is turned.Which of the pictures below is obtained?(A) (B) (C) (D) (E)13. Felix the rabbit has 20 carrots. Every day he eats 2 of them.He has eaten the 12th carrot on a Wednesday.On which day of the week did he start eating the carrots?(A) Monday (B) Tuesday (C) Wednesday (D) Thursday (E) Friday14. A rose bush has 8 flowers on which butterflies and dragonflies are sitting.On every flower there is at most one insect sitting on it. More than half of theflowers are occupied.The number of butterflies is twice as big as the number of dragonflies.How many butterflies are sitting on the rose blossoms?(A) 2 (B) 3 (C) 4 (D) 5 (E) 615.The map shows the roundtrip that Captain Bluebearcovers during his journey. Three distances are given onthe map.He sails from island to island and starts at the islandBerg. In total he covers a distance of 100 km. Thedistances between the islands Wüste and Wald is equalto the distance between the islands Berg and Blume viaVulkan.How big is the distance between Berg and Wald?(A) 17 km (B) 23 km (C) 26 km (D) 33 km (E) 35 km16. T obias glues 10 cubes together so that the following object is formed:He paints all of it, even the bottom.How many cubes then have exactly 4 faces coloured in?(A) 6 (B) 7 (C) 8 (D) 9 (E) 10- 5 Point Examples -17. T he big rectangle consists of various squares of different sizes.Each of the three smallest squares has area 1.How big is the area of the big rectangle?(A) 65 (B) 71 (C) 77 (D) 87 (E) 9818. I n order to slay a dragon, Mathias has to cut off all of its heads. As soon as he has cut off 3 heads, a new onegrows back immediately. After Mathias has cut off 13 heads the dragon is dead.How many heads did the dragon have initially?Start(A) 8 (B) 9 (C) 10 (D) 11 (E) 1219. T he rooms in Kanga’s house are numbered. Eva enters the house through themain entrance. Eva has to walk through the rooms in such a way that each roomthat she enters has a number higher than the previous one.Through which door does Eva leave the house?(A) A (B) B (C) C (D) D (E) E20. T he symbols stand for one of the digits 1, 2, 3, 4 or 5.It is known thatWhich symbol stands for the digit 3?(A) (B) (C) (D) (E)21. A belt can be joined together in 5 different ways.How many cm is the belt longer if it is only closed in the first hole instead of in all 5 holes?(A) 4 cm (B) 8 cm (C) 10 cm (D) 16 cm (E) 20 cm22. A decorated glass tile is mirrored several times along the boldly printed edge. The first mirror image is shown.spiegelnWhat does the tile on the far right look like after the third reflection?(A) (B)(C) (D) (E)23. L ea should write the numbers 1 to 7 in the fields of the given figure. There is only onenumber allowed in every field.Two consecutive numbers are not allowed to be in adjacent fields. Two fields areadjacent if they have one edge or one corner in common.Which numbers can she write into the field with the question mark?(A) all 7 numbers (B) only odd numbers (C) only even numbers (D) the number 4 (E) the numbers 1or 724. E ach of the four balls weighs either 10 or 20 or 30 or 40 grams.Which ball weighs 30 grams?(A) A (B) B (C) C (D) D (E) It can be A or B.Känguru der Mathematik 2018Group Benjamin (Grade 5 and 6)Austria – 15. 3. 2018- 3 Points Examples -1. As seen in the diagram, three darts are thrown at nine fixedballoons. If a balloon is hit it will burst and the dart continues in thesame direction it had beforehand. How many balloons will not behit by a dart?(A) 2 (B) 3 (C) 4 (D) 5 (E) 62. Peter places threebuilding blocks on a table, asshown.What does he see when he islooking at them from above?(A) (B) (C) (D) (E)3. If you hit the target board, you score points.The number of points depends on which one of the three areas youhit. Diana throws two darts, three times at the target board. On thefirst attempt she scores 14 points and on the second 16 points.How many points does she score on the third attempt?(A) 17 (B) 18 (C) 19 (D) 20 (E) 22 14 Points 16 Points ???4. A garden is split into equally sized square-shaped lots. A fast and a slow snail crawl in different directions along the outside edge of the garden. Both start at the corner S. The slowsnail crawls 1 m in one hour and the fast one crawls 2 m in one hour.In which position will the two snails meet for the first time?(A) A (B) B (C) C (D) D (E) E5. A star consist of a square and four triangles. Allsides of the triangles are equally long. The perimeter of the square is 36 cm. What is the perimeter ofthe star?(A) 144 cm (B) 120 cm (C) 104 cm (D) 90 cm (E) 72 cm6. A big spot of ink covers most of a calendar page of a certain month.Which day of the week does the 25th day of that month fall on?(A) Monday (B) Wednesday (C) Thursday (D) Saturday (E) Sunday7. How many times do you have to roll an ordinary die in order to be certain that at least onenumber is rolled twice?(A) 5 (B) 6 (C) 7 (D) 12 (E) 188. A figure is made up of three squares. The side length of the smallest square is 6 cm. How longis the side length of the biggest square?(A) 8 cm (B) 10 cm (C) 12 cm (D) 14 cm (E) 16 cm- 4 Point Examples -9. Alice subtracts one two-digit number from another two-digit number.Afterwards she paints over two digits in the calculation.How big is the sum of the two painted digits?(A) 8 (B) 9 (C) 12 (D) 13 (E) 1510. In the diagram the circles represent light bulbs which are connected to someother light bulbs. Initially all light bulbs are switched off. If you touch a light bulbthen that light bulb and all directly adjacent light bulbs switch themselves on. Whatis the minimum number of light bulbs you have to touch in order to switch on allthe light bulbs?(A)2 (B) 3 (C) 4 (D) 5 (E) 611. Four equally big squares are partiallycoloured in black.In which of the four squares is the totalarea of the black parts biggest?(A) A (B) B (C) C (D)D (E) The total area of the black parts is always equally big.12. The four smudges hide four of the numbers 1, 2, 3, 4, 5. The calculationsalong the two arrows are correct.Which number hides behind the smudge with the star?(A) 1 (B) 2 (C) 3 (D) 4 (E) 513. A lion hides in one of three rooms. On the door to room number 1 a note reads: …The lion is not here“. On the door to room number 2 a note reads: …The lion is here“. On the door to room number 3 a note reads: …2 + 3 = 5“. Exactly one of the three notes is true. In which room is the lion?(A) Room 1 (B) Room 2 (C) Room 3(D) It can be in any room. (E) It is either in room 1 or room 2.14. The two girls Eva and Olga and the three boys Adam, Isaac and Urban play together with a ball. If a girl has the ball she throws it either to the second girl or to a boy. Every boy only throws the ball to another boy, however not to the one where the ball has just come from. The first throw is made by Eva to Adam. Who makes the 5th throw?(A) Adam (B) Eva (C) Isaac (D) Olga (E) Urban15. The faces of a die are either white, grey or black. Opposite faces are always a different colour. Which of the following nets does not belong to such a die?(A) (B) (C) (D) (E)16. From a list with the numbers 1, 2, 3, 4, 5, 6, 7, Monika chooses 3 different numbers whose sum is 8. From the same list Daniel chooses 3 different numbers whose sum is 7. How many of the numbers were chosen by both Monika and Daniel?(A) none (B) 1 (C) 2 (D) 3 (E) It cannot be determined.- 5 Point Examples - 17. Emily wants to write a number into every free small triangle. The sum of the numbers in two triangles with a common side should always be the same. Two numbers are alreadygiven. How big is the sum of all numbers in the figure?(A) 18 (B) 20 (C) 21 (D) 22 (E) it cannot be calculated18. Instead of digits Hannes uses the letters A, B, C and D in a calculation. Different letters stand fordifferent digits. Which digit does the letter B stand for?(A) 0 (B) 2 (C) 4 (D) 5 (E) 619. Four ladybirds each sit on adifferent cell of a 4 x 4 grid. One isasleep and does not move. On awhistle the other three each move toan adjacent free cell.They can crawl up, down, to the rightor to the left but are not allowed on any account to move back to the cell that they have just come from.Where could the ladybirds be after the fourth whistle? (A)(B) (C) (D) (E)20. The five balls weigh 30 g,50 g, 50 g, 50 g and 80 g.Which of the balls weighs30 g?(A) A (B) B (C) C (D) D (E) E21. Three different digits A, B and C are chosen. Then the biggest possible six-digit number is built where the digit A appears 3 times, the digit B 2 times and the digit C 1 time.Which representation is definitely not possible for this number?(A) AAABBC (B) CAAABB (C) BBAAAC (D) AAABCB (E) AAACBB22. The sum of Kathi ’s age and the age of her mother is 36. The sum of the age of her mother and the age of her grandmother is 81. How old was Kathi ’s grandmother when Kathi was born?(A) 28 (B) 38 (C) 45 (D) 53 (E) 5623. Nick wants to split the numbers 2, 3, 4, 5, 6, 7, 8, 9, 10 into some groups so that the sum of the numbers in each group is equally big. What is the biggest number of groups he can build this way?(A) 2 (B) 3 (C) 4 (D) 6 (E) another number24. The figure shown on the right consists of one square part and eight rectangular parts. Eachpart is 8 cm wide. Peter assembles all parts to form one long, 8 cm wide rectangle. How long isthis rectangle?(A) 150 cm (B) 168 cm (C) 196 cm (D) 200 cm (E) 232 cmInitial position After the first whistle After the second whistle After the third whistle- 3 Point Examples - 1. Which result is obtained by the calculation (20+18)∶(20−18)?(A) 18 (B) 19 (C) 20 (D) 34 (E) 362. If the letters of the Word MAMA are written underneath each other then the word has a vertical axis of symmetry. For which of these words does that also hold true?(A) ADAM (B) BAUM (C) BOOT (D) LOGO (E) TOTO3. A triangle ABC has side lengths 6 cm, 10 cm and 11 cm. An equilateral triangle XYZ has the same perimeter as the triangle ABC. What are the side lengths of the triangle XYZ?(A) 6 cm (B) 9 cm (C) 10 cm (D) 11 cm (E) 27 cm4. Which number has to replace the ✩ in the calculation so that it is true? (A) 8(B) 9 (C) 10 (D) 12 (E) 155. The fence on the right has many holes. One morning the fence falls over and lies on thefloor. Which of the following pictures shows the fallen down fence? (A)(B)(C) (D)(E)6.Bernd produces steps for a staircase which are 15 cm high and 15 cm deep (see diagram). The staircase should reachfrom the ground floor to the first floor which is 3 m higher.How many steps does Bernd have to produce?(A) 8(B) 10(C) 15(D)20(E) 257.In a game of luck, A ball rolls downwards towards hammered nails and is diverted either tothe right or the left by a nail immediately below it. One possible path is shown in the diagram. How many different ways are there for the ball to reach the second compartment from theleft?(A) 2 (B) 3 (C) 4 (D) 5 (E) 68. A large rectangle is made up of 9 equally big rectangles. The longer side of each smallrectangle is 10 cm long. What is the perimeter of the large rectangle?(A) 40 cm (B) 48 cm (C) 76 cm (D) 81 cm (E) 90 cm9. Two circles are inscribed into an 11 cm long and 7 cm wide rectangle so that they eachtouch three sides of the rectangle. How big is the distance between the centres of the twocircles?(A) 1 cm (B) 2 cm (C) 3 cm (D) 4 cm (E) 5 cm10. The square ABCD has side length 3 cm. The points M and N, which lie on the sides AD and ABrespectively, are joined to the corner C. That way the square is split up into three parts withequal area. How long is the line segment DM?(A) 0.5 cm (B) 1 cm (C) 1.5 cm (D) 2 cm (E) 2.5 cmKänguru der Mathematik 2018 Level Kadett (Grade 7 and 8) Austria – 15. 3. 20182 ⋅ 18 ⋅ 14 = 6 ⋅ ✩ ⋅ 7- 4 Point Examples -11. Martina multiplies two, two-digit numbers and then paints over some ofthe digits. How big is the sum of the three digits that Martina has painted over?(A) 5 (B) 6 (C) 9 (D) 12 (E) 1412. A rectangle is split up into 40 equally big squares. The rectangle consists of more than one row of squares. Andreas colours in all squares of the middle row. How many squares did he not colour in?(A) 20 (B) 30 (C) 32 (D) 35 (E) 3913. Philipp wants to know how much his book weighs correct to half a gram. However, his scale only shows correct to 10 g and therefore he weighs several identical books all together. What is the minimum number of identical books he has to put on the scale in order to reach his aim?(A) 5 (B) 10 (C) 15 (D) 20 (E) 5014. A lion hides in one of three rooms. On the door to room number 1 a note reads: …The lion is here“. On the door to room number 2 a note reads: …The lion is not here“. On the door to room number 3 a note reads: …2 + 3 = 2 x 3“. Exactly one of the three notes is true. Which room is the lion in?(A) Room 1 (B) Room 2 (C)Room 3(D) It can be in any room. (E) It is either in room 1 or room 2.15. Valentin draws a zig-zag line insidea rectangle as shown in the diagram. For that he uses the angles 10°, 14°, 33°and 26°. How big is angle ?(A) 11° (B) 12° (C) 16° (D) 17° (E) 33°16. Alice writes down three prime numbers that are all less than 100. Sheonly uses the digits 1, 2, 3, 4 and 5, in fact she uses each digit exactly once.Which of the following prime numbers did she definitely write down?(A) 2 (B) 5 (C) 31 (D) 41 (E) 5317. A hotel in the carribean correctly advertises using the slogan: …350 days of sun in the year!” How many days does Mr. Happy have to spend in the hotel in a year with 365 days to be guaranteed to have two consecutive days of sunshine to enjoy?(A) 17 (B) 21 (C) 31 (D)32 (E) 3518. The diagram shows a rectangle and a straight line x, which is parallel to oneof the sides of the rectangle. There are two points A and B on x inside therectangle. The sum of the areas of the two triangles shaded in grey is 10 cm².How big is the area of the rectangle?(A) 18 cm2(B)20 cm2(C) 22 cm2(D) 24 cm2(E) It depends on the position of the points A and B.19. Jakob writes one of the natural numbers 1 to 9 into each cell of the 3x3-table. Then he worksout the sum of the numbers in each row and in each column. Five of his results are 12, 13, 15, 16and 17. What is the sixth sum?(A) 17 (B) 16 (C) 15 (D) 14 (E) 1320. 11 points are marked left to right on a straight line and their distances recorded. The sum of the distances from the first point to every other point is 2018. The sum of all distances from the second point to every other point, including the first point, is 2000. What is the distance between the first and the second point?(A) 1 (B) 2 (C) 3 (D) 4 (E) 5- 5 Point Examples -21. At an election for student representatives there are three candidates. 130 students have voted. The candidate that has the most votes wins. Currently Samuel has 24, Kevin 29 and Alfred 37 votes. How many of the currently not yet counted votes does Alfred need to get in order to definitely win the election?(A) 13(B) 14(C) 15(D) 16(E) 1722. The diagram shows the net of a box consisting onlyof rectangles. How big is the volume of the box?(A) 43 cm3(B) 70 cm3(C) 80 cm3(D) 100 cm3(E) 1820 cm323. Rita wants to write a number into everysquare of the diagram shown. Every numbershould be equal to the sum of the twonumbers from the adjacent squares. Squaresare adjacent if they share one edge. Two numbers are already given. Which number isshe going to write into the square marked with x?(A) 10(B) 7(C) 13(D) −13(E) −324. Simon runs along the edge round a 50 m long rectangular swimming pool, while at the sametime Jan swims lengths in the pool. Simon runs three times as fast as Jan swims. While Jan swims6 lengths, Simon manages 5 rounds around the pool. How wide is the swimming pool?(A) 25 m (B) 40 m (C) 50 m (D) 80 m (E) 180 m25. Lisas aviation club designs a flag with a flying …dove“ on a 4x6-grid. The area of the…dove“ is 192 cm2. The perimeter of the …dove“ is made up of straight lines and circulararcs. What measurements does the flag have?(A) 6 cm x 4 cm (B) 12 cm x 8 cm (C) 20 cm x 12 cm(D) 24 cm x 16 cm (E) 30 cm x 20 cm26. The points N, M and L lie on the sides of an equilateral triangle ABC so thatNM ⊥ BC, ML ⊥ AB and LN ⊥ AC holds true. The area of the triangle ABC is 36 cm2.What is the area of the triangle LMN?(A) 9 cm² (B) 12 cm² (C) 15 cm² (D) 16 cm² (E) 18 cm²27. Anna, Bettina and Claudia go shopping. Bettina spends 85% less than Claudia.Anna spends 60% more than Claudia. Together they spend 55 €. How much moneydoes Anna spend?(A) 3 €(B) 20 € (C) 25 € (D) 26 € (E) 32 €28. Viola practices long-jumping. On average she has jumped 3.80 m so far. On the next jump she reaches 3.99 m and thus the mean increases to 3.81 m. How far does she have to jump on her next attempt in order to increase her mean to 3.82 m?(A) 3.97 m (B) 4.00 m (C) 4.01 m (D) 4.03 m (E) 4.04 m29. In the isosceles triangle ABC (with base AC) the points K and L are added on the sidesAB and BC respectively so that AK = KL = LB and KB = AC. How big is the angle ∠ ABC?(A) 30° (B) 35° (C) 36° (D) 40° (E) 44°30. In a game of dominoes the tiles always have to be placed so that the touching halves oftwo adjacent domino tiles show the same number of dots. Paul has six domino tiles in front of him (see diagram).In several steps Paul tries to arrange them in a correct order. In each step he is either allowed to swap any two domino tiles or he is allowed to turn one domino tile 180° around. What is the minimum number of steps he needs in order to arrange the domino tiles correctly?(A) 1 (B) 2 (C) 3 (D) 4 (E) This is impossible.Känguru der Mathematik 2018Level Junior (Grade 9 and 10)Austria – 15.3.2018- 3 Point Examples -1. Every child in my family has at least two brothers and at least one sister. What is theminimum number of children in my family?(A) 3 (B) 4 (C) 5 (D) 6 (E) 72. The rings shown are partially interlinked. How long is the longest chain built this waywhich also contains the thick light ring?(A) 3 (B) 4 (C) 5 (D) 6 (E) 73. In a triangle one side has length 5 and another side has length 2. The length of the third side is an odd whole number. Determine the length of the third side.(A) 3 (B) 4 (C) 5 (D) 6 (E) 74. The distance between the top of the cat that is sitting onthe table to the top of the cat that is sleeping on the floor is150 cm. The distance from the top of the cat that is sleepingon the table to the top of the cat that is sitting on the floor is110 cm. How high is the table?(A) 110 cm (B) 120 cm (C) 130 cm (D) 140 cm (E) 150 cm5. The sum of 5 consecutive whole numbers is 102018. What is the middle number of those numbers?(A) 102013(B) 52017(C) 102017(D) 22018(E) 2∙ 1020176. In the three regular hexagons shown, X, Y and Z describe in this orderthe areas of the grey shaded parts. Which of the following statementsis true?(A)X=Y=Z(B) Y=Z≠ X(C) Z=X≠ Y(D) X=Y≠ Z(E) Each of the areas has a different value.7. Maria wants to divide 42 apples, 60 peaches and 90 cherries fairly amongst her friends. In order to do so she divides the entire fruit into baskets, each with the same amount of apples, peaches and cherries, to then give each of her friends one such basket with fruit. At most, how many baskets of fruit can she fill this way?(A) 3 (B) 6 (C) 10 (D) 14 (E) 428. In the (correct) calculation shown, some of the digits were replaced by the letters P, Q, R and S.What is the value of P + Q + R + S?(A) 14 (B)15 (C) 16 (D) 17 (E) 249. How big is the sum of 25 % of 2018 and 2018 % of 25?(A)1009 (B) 2016 (C) 2018 (D) 3027 (E) 504510. In the diagram shown, you should follow the arrows to get from A to B.How many different ways are there that fulfill this condition?(A) 20(B)16(C) 12(D) 9(E) 611. The entrances of two student halls lie in a plain street 250 m apart from each other. There are 100 students in the first one and 150 students in the second one. Where should a bus stop be built if the total sum of the distances that each student of both halls has to cover to get to the bus stop should be a minimum?(A) directly in front of the first hall (B) 100 m away from the entrance of the first hall(C) 100 m away from the entrance of the second hall (D) directly in front of the second hall(E) in any place between the two hall entrances12. 105 numbers are written in a row: 1,2,2,3,3,3,4,4,4,4,5,5,5,5,5,...Where each number n is written exactly n-times. How many of those numbers are divisible by 3?(A) 4 (B) 12 (C) 21 (D) 30 (E) 4513. Eight congruent semi-circles are drawn inside a square with side length 4. How big is thearea of the white part?(A) 2π(B)8(C) 6+π(D) 3π−2(E) 3π14. On one particular day there are a total of 40 trains from one of the towns M, N, O, P and Q to exactly one other of those towns. There are 10 trains either from or to M. There are 10 trains either from or to N. There are 10 trains either from or to O. There are 10 trains either from or to P. How many trains are there either from or to Q?(A) 0 (B) 10 (C) 20 (D) 30 (E) 4015. At a humanistic university you can study languages, history and philosophy. Some of the students there study exactly one language. (Nobody studies several languages at the same time.) Amongst those, 35 % study English. Amongst all students of the university 13 % study a language other than English. Which percentage of the students studies a language?(A) 13 % (B)20 % (C) 22 % (D) 48 % (E) 65 %16. Peter wants to buy a book but has no money. He can only buy this book with his father's and his two brother's help. His father gives him half as much money as his brothers give him jointly. His older brother gives him a third of the sum that the two others give him. The youngest brother gives him 10 €. How expensive is the book?(A)24 €(B) 26 €(C) 28 €(D) 30 €(E) 32 €17. How many three-digit numbers are there with the property that the two-digit number obtained by deleting the middle number is exactly a ninth of the original number?(A) 1 (B) 2 (C) 3 (D)4 (E) 518. How often does the summand 2018² appear under the root, if the following statement is correct?√20182 + 20182 + … + 20182=201810(A) 5(B) 8(C) 18(D) 20188(E)201818∙ 102018 ∙ (102018−1)?19. How many digits has the final result of the calculation 19(A) 2017 (B) 2018 (C) 4035 (D)4036 (E) 403720. In a regular 2018-sided shape the vertices are numbered 1 to 2018 in order. Two diagonals of the polygon are drawn in, where one of them connects the vertices 18 and 1018 and the other one the vertices 1018 and 2000. How many vertices do the three resulting polygons have?(A)38, 983, 1001 (B) 37, 983, 1001 (C) 38, 982, 1001 (D) 37, 982, 1000 (E) 37, 983, 1002。
Singapore Math Kangaroo Contest 2018Rough WorkingSection A(Correct–3points|Unanswered–0points|Wrong–deduct1point)Question1In a family,each child has at least two brothers and at least one sister.What is the smallest possible number of children in the family?(A)3(B)4(C)5(D)6(E)7Question2Some of the rings in the picture form a chain that includes the ring indicated by the arrow.How many rings are there in the longest possible chain?(A)3(B)4(C)5(D)6(E)7Question3The lengths of the two sides of the triangle are5and2,and the length of the third side is an odd number.Find the length of the third side.(A)3(B)4(C)5(D)6(E)7Question4The distance from the sleeping cat on thefloor to the top of the cat sitting on the table is150cm as shown in the picture below.The distance from the cat sitting on thefloor to the cat sleeping on the table is110cm as(A)110cm(B)120cm(C)130cm(D)140cm(E)150cmThe sum of5consecutive integers is102018.What is the middle number?(A)102013(B)52017(C)102017(D)22018(E)2·102017 Question6Given three congruent hexagon,A,B and C represents the total area of the shaded region in each regular hexagon as statements is true?(A)A=B=C(B)B=C=A(C)C=A=B(D)A=B=C(E)A=B=CQuestion7Mary has collected42apples,60apricots and90cherries.She wants to divide them into identical piles using all of the fruit and then give a pile to each of her friends.What is the most number of piles she can make?(A)3(B)6(C)10(D)14(E)42Question8Some of the digits in the following correct addition have been replaced by the letters P,Q,R and S, as shown.What is the value of P+Q+(A)14(B)15(C)16(D)17(E)24What is the sum of25%of2018and2018%of25?(A)1009(B)2016(C)2018(D)3027(E)5045 Question10How many different routes are there from A to B along the lines following the directions of the arrows as shown in the picture below?BA(A)20(B)16(C)12(D)9(E)6Section B(Correct–4points|Unanswered–0points|Wrong–deduct1point)Question11Two buildings are located on one street at a distance of250metres from each other.There are100 students living in thefirst building,and there are150students living in the second building.Where should a bus stop be built so that the total distance that all residents of both buildings have to walk from this bus stop to their buildings would be the least possible?(A)in front of thefirst building(B)100metres from thefirst building(C)100metres from the second building(D)in front of the second building(E)anywhere between the buildingsQuestion12There are105numbers written in a row:1,2,2,3,3,3,4,4,4,4,5,5,5,5,5,...(Each number n is written exactly n times).How many of these numbers are divisible by3?(A)4(B)12(C)21(D)30(E)45Eight congruent semicircles are drawn inside a square of length4.What is the area of the non-shaded part of the square?(A)2π(B)8(C)6+π(D)3π−2(E)3πQuestion14On a certain day40trains each travelled between two of the towns M,N,O,P and Q.10trains travelled either from M or to M.10trains travelled either from N or to N.10trains travelled either from O or to O.10trains travelled either from P or to P.How many trains travelled from Q or to Q?(A)0(B)10(C)20(D)30(E)40Question15At the University of Humanities you can study languages,history and philosophy.35%of students that study languages,study English.13%of the university students study a language other than English.No student studies more than one language.What percentage of the university students study languages?(A)13%(B)20%(C)22%(D)48%(E)65% Question16Peter wanted to buy a book,but he didn’t have any money.He bought it with the help of his father and his two brothers.His father gave him half of the amount given by his brothers.His elder brother gave him one third of what the others gave.The younger brother gave him10EUR.What was the price of the book?(A)24EUR(B)26EUR(C)28EUR(D)30EUR(E)32EURHow many3-digit numbers are there with the property that the2-digit number obtained by removing the middle digit in the number is equal to one ninth of the original3-digit number?(A)1(B)2(C)3(D)4(E)5Question18In the calculation shown,how many times does the term20182appear inside the square root to make the calculation correct?20182+20182+...+20182=201810(A)5(B)8(C)18(D)20188(E)201818Question191×102018×(102018−1)=x.How many digits are there in the value of x9(A)2017(B)2018(C)4035(D)4036(E)4037Question20There are two diagonals drawn in a regular polygon with2018sides and its vertices are numbered from1to2018.One diagonal connects the vertices with the numbers18and1018,the other connects the vertices with the numbers1018and2000.How many vertices do the resulting three polygons have?(A)38,983,1001(B)37,983,1001(C)38,982,1001(D)37,982,1000(E)37,983,1002Section C(Correct–5points|Unanswered–0points|Wrong–deduct1point)Question21Several integers are written on a blackboard,including the number2018.The sum of all these integers is2018.The product of these integers is also2018.Which of the following could be the number of integers written on the blackboard?(A)2016(B)2017(C)2018(D)2019(E)2020Question22Four positive numbers are given.You choose three of them,calculate their arithmetic mean and then add the fourth number.This can be done in four different ways.The results are17,21,23and29 respectively.What is the largest of the given four numbers?(A)12(B)15(C)21(D)24(E)29Question23The points A0,A1,A2,...lie on a line such that A0A1=1and the point A n is the midpoint of the segment A n+1A n+2for every non-negative integer n.What is the length of the segment A0A11? (A)171(B)341(C)512(D)587(E)683Question24Two concentric circles of radii1and9make a ring.In the interior of this ring n circles are drawn without overlapping,each being tangent to both of the circles of the ring(an example of such shape for n=1and different radii is shown in the picture).What is the largest possible value for n?(A)1(B)2(C)3(D)4(E)5A regular polygon with18vertices where each number written on the vertices is equal to the sum of the numbers at the two adjacent vertices.Two of the numbers are given.What number should be written at the vertex A?(A)2018(B)-20(C)18(D)38(E)-38Question26Diana draws a rectangular grid of12squares.Some of the squares are painted black.In each blank square she writes the number of black squares that shares a side with it.Thefigure shows an example. Now she does the same in a rectangular grid with2018squares.What is the maximum value that she can obtain as the result of the sum of all the numbers in the grid?(A)1262(B)2016(C)2018(D)3025(E)3027 Question27Seven small cubes have been removed from a3×3×3cube(see the picture).We cut this cube by the plane passing through the centre of the cube and perpendicular to one of its four big diagonals. What will the cross-section look like?(A)(B)(C)(D)(E)Each number of the set {1,2,3,4,5,6}is written exactly into one of the square in a 2×3table.In how many ways can this be done such that in each row and in each column the sum of the numbers is divisible by 3?(A )36(B )42(C )45(D )48(E )another number Question 29Ed made a large cube by gluing together a number of small identical cubes and then he painted some of the faces of the large cube.His sister Nicole dropped the cube and it broke into the original small cubes.45of these small cubes didn’t have any painted faces.How many faces of the large cube did Ed paint?(A )2(B )3(C )4(D )5(E )6Question 30Two chords AB and AC are drawn in a circle with diameter AD .The angle ∠BAC =600,BE ⊥AC ,AB =24cm,EC =3cm.What is the length of the chord BD ?(A )√3cm (B )2cm (C )3cm (D )2√3cm (E )3√2cm。