2017-2018年度六年级美国数学大联盟杯赛(中国赛区)初赛

2017-2018年度美国“数学大联盟杯赛”(中国赛区)初赛(四年级)(初赛时间：2017年11月26日，考试时间90分钟，总分200分)学生诚信协议：考试期间，我确定没有就所涉及的问题或结论，与任何人、用任何方式交流或讨论，我确定我所填写的答案均为我个人独立完成的成果，否则愿接受本次成绩无效的处罚。

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选择题：每小题5分，答对加5分，答错不扣分，共200分，答案请填涂在答题卡上。

1.Which of the following is the smallest?A) 2.018 B) 20.18 C) 0.218 D) 20182.What is the least common multiple of 20 and 18?A) 90 B) 180 C) 240 D) 3603.The sum of the degree-measures of the exterior angles of a triangle is?A) 180 B) 360 C) 540 D) 7204.In the figure on the right, please put the numbers 1 – 11 in the elevencircles so that the three numbers in every straight line add up to 18.What is the number in the middle circle? Note: There are 5 straightlines in total in this figure.A) 6 B) 7 C) 8 D) 95.I am a lovely cat. When I multiply the digits of a whole numberand the product I get is 8, I put that whole number on my list offavorite numbers. Of the whole numbers from 1000 to 9999,how many would I put on my list of favorite numbers?A) 10 B) 12 C) 16 D) 206.Two planes take off at the same time from the same point to race to apoint and back. Place A travels at 180 miles per hour on the way out and240 miles per hour on the return trip. Plane B covers the entire distance at an averagespeed of 210 miles per hour. Which plane wins the race, or is it a tie?A) plane A wins B) plane B winsC) a tie D) non-deterministic 7.52 × 88 = 44 ×?A) 102 B) 96 C) 104 D) 1248.What is the smallest whole number that leaves a remainder of 4, 5, 6 when divided byeach of 5, 6, 7?A) 29 B) 209 C) 210 D) 20099.In △ABC, m∠A + m∠C = m∠B. What is the degree measure of ∠B?A) 80 B) 90 C) 100 D) 18010.I bought a toy for $10, sold it for $20, rebought it for $30, and resold it for $40. My totalprofit on the 4 transactions was ?A) 10 B) 20 C) 30 D) 4011.What is the greatest number of integers I can choose from the first ten positive integers sothat any 3 of the chosen integers could be the lengths of the three sides of a triangle?A) 4 B) 5 C) 6 D) 712.How many whole numbers between 200 and 400 have all their digits increasing in valuewhen read from left to right?A) 30 B) 36 C) 42 D) 4813.What is the value of 1% of 10% of 100?A) 0.01 B) 0.1 C) 1 D) 1014.If three cats can eat three bowls of food in three minutes, how many minutes will it take100 cats to eat 100 bowls of food?A) 1 B) 3C) 100 D) None of the above15.There are three squares. The area of the smallest one is 2. The side-length of the secondsquare is twice the side-length of the smallest one. And the side-length of the third square is three-times the side-length of the smallest one. The total area of the three squares isA) 12 B) 28 C) 36 D) 7216.A man, who had been married for three years, spent25of his yearly income on his family,14on business, and110on personal travel. If he saved $45000 during those three years, what was his annual income?A) $45000 B) $50000C) $65000 D) None of the above17.Given four different integers, at most how many different sums can be formed bychoosing two, three, or four of them and finding each sum?A) 8 B) 9 C) 10 D) 1118. Max places 100 eggs in 10 baskets, with each basket receiving at least1 egg, but no2 baskets receiving the same number of eggs. What is the greatest number of eggs that may be placed in a basket?A) 45 B) 47 C) 55 D) 6519. 2 + 3 × 4 – 5 =A) 0 B) 6 C) 9 D) 15 20. What is the highest power of 2 that divides 2 × 4 × 6 × 8 × 10? A) 25 B) 27 C) 28 D) 215 21. Which of the following is a prime number?A) 2017B) 2018C) 2015D) 201622. What is the greatest possible number of acute angles in a figure consisting of a triangleand a line passing through two sides of the triangle?A) 5B) 6C) 7D) 823. Amy can solve 5 questions every 3 minutes. Kate can solve 3 questions every 5 minutes.How many more questions Amy can solve than Kate in one hour?A) 15B) 32C) 60D) 6424. Using 3 Ts and 2 Js, in how many different orders can the five letters be arranged? Forexample, TTTJJ and TTJJT are two such different orders.A) 2B) 10C) 20D) 6025. Coastal Coconuts can divide all their coconuts evenly among 8, 9, or10 customers, with 1 coconut left over each time. If Coastal Coconuts has more than 1 coconut, what is the least number of coconuts they could have?A) 561 B) 721C) 831 D) None of the above 26. 35 ÷ 32 =A) 3 B) 9 C) 27 D) 81 27. If the sum of three prime numbers is 30, what is the least prime number?A) 2B) 3C) 5D) 728. Juxtaposing two identical squares to form a rectangle, the perimeter of the rectangle is 12less than the sum of the perimeter of the two squares. What is the side-length of the original square?A) 3B) 6C) 9D) 1229. It takes Mike 2 hours to finish a task. It takes 4 hours for Tom to finish the same task.Mike and Tom worked together on this task for one hour before Mike had to leave. How long will it take Tom to finish the rest of the task?A) 1 B) 2 C) 3 D) 4 30. The number of triangles in the figure on the right isA) 9 B) 10 C) 11 D) 12 31. What is the thousands digit of the product 1234560 × 2345670 × 3456780?A) 8B) 6C) 5D) 032. The sum of nine consecutive positive integers is always divisible byA) 2B) 5C) 7D) 933. You can put as many as 96 books in 6 backpacks. How many backpacks are necessary for144 books?A) 7B) 8C) 9D) 1034. The number of nickels I have is twice the number of dimes I have, and together thesecoins are worth more than $1. The least number of dimes that I can have isA) 5B) 6C) 8D) 1035. The ages of four kids are four consecutive positive integers. The product of their ages is3024. How old is the oldest kid?A) 8B) 9C) 10D) 1136. In the Game of Life, you earn 3 points for flipping a coin to “heads”, and 5 points forflipping a coin to “tails”. In all, how many positive whole number scores are IMPOSSIBLE to get after flipping it one or more times?A) 4B) 5C) 7D) 1137. Four monkeys can eat four bags of peanuts in three minutes. How many monkeys will ittake to eat 100 bags of peanuts in one hour?A) 4 B) 5 C) 20 D) 100 38. The tens digit of the product of the first 100 positive integers isA) 2B) 4C) 8D) 039. Someone put three dimes into my pile of quarters. If I add up the value of these coins,including the dimes, the sum could beA) $6.25B) $7.75C) $8.05D) $9.5040. Brooke's empty tub fills in 20 minutes with the drain plugged, andher full tub drains in 10 minutes with the water off. How manyminutes would it take the full tub to drain while the water is on?A) 12B) 15 C) 20 D) 30。

37. 将 1 ~ 9 九个数不重不漏地组成一个两位数、一个三位数、一个四位数。 这三个数均能被 9 整除，并且 7、8、9 分别在这三个数中，三个数十位 数字为三个连续的偶数，个位数字为三个连续的奇数。如果将四位数的 千位移到两位数的百位，组成新的三个三位数，新的三位数也均能被 9 整除。那么题中最初的三位数是 。 38. 如图为一个正方体有盖纸盒的示意图，在 1 ~ 30 的数中 选出 7 个，在纸盒的每个面填一个数。将盒盖的两个数 字相加后，三组相对面填的数均满足两两乘积相等。那 么 x 处的数字有 种可能。
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A) 413 B) 1626 C) 21155 D) 161155 16. Which of the following figures has an odd number of sides? A) rhombus B) trapezoid C) pentagon D) hexagon 17. For how many integers from 55 to 66 is the ones digit greater than the tens digit? A) 4 B) 5 C) 10 D) 11 18. Lex buys 6 same-priced books and pays with a $50 bill. The change Lex receives is twice the price of a book. Each book costs A) $6.25 B) $7.14 C) $8.33 D) $12.50
14. If two consecutive whole numbers have a different number of digits, then their 一、选择题(每小题 5 分，答对加 5 分，答错不扣分，共 150 分，答案请填涂在答题卡上) 1. The band’s trombone plays 2013 notes, the trumpet plays 2014 notes, and the tuba plays 218 notes. That’s a total of ? notes. A) 6245 B) 6045 C) 4245 D) 645 2. The remainder when (999 999 999 + 666 666 + 333 + 1) is divided by 3 is A) 0 B) 1 C) 2 D) 3 3. 20 − 5 × 2 = 2 × ? A) 5 B) 15 C) 25 D) 30 C) 15 D) 100

三等獎 金獎 銀獎 銅獎 銅獎 銀獎 金獎 銅獎 銀獎 銀獎 銅獎 金獎 金獎 銅獎 銀獎 優異獎 優異獎 優異獎 優異獎

梁昫妍 第十屆《兒童英語創意寫作及演講比賽-香港站》決賽 劉芷筠 第十屆《兒童英語創意寫作及演講比賽-香港站》決賽 歐陽佩喬 五育中學 ─「2017 小學多元繽紛同樂日」通識徵文比賽 鄭凌怡 五育中學 ─「2017 小學多元繽紛同樂日」通識徵文比賽 鄧俊研 五育中學 ─「2017 小學多元繽紛同樂日」通識徵文比賽 鄺顯曦 五育中學 ─「2017 小學多元繽紛同樂日」通識徵文比賽 黃晉其 五育中學 ─「2017 小學多元繽紛同樂日」通識徵文比賽 吳卓庭 五育中學 ─「2017 小學多元繽紛同樂日」通識徵文比賽 楊鎧汶 五育中學 ─「2017 小學多元繽紛同樂日」通識徵文比賽 麥晴懿 五育中學 ─「2017 小學多元繽紛同樂日」通識徵文比賽 張子航 五育中學 ─「2017 小學多元繽紛同樂日」中文寫作比賽 楊殷穎 五育中學 ─「2017 小學多元繽紛同樂日」中文寫作比賽 林唯廉 五育中學 ─「2017 小學多元繽紛同樂日」英文寫作比賽
浸信會呂明才小學 2017-2018 年度 課外活動組
2017-2018 年度校外比賽參賽/獲獎數目
上學期 下學期 全年總數 參賽項目 獲獎人數 參賽項目 獲獎人數 參賽項目 獲獎人數 6 597 7 331 13 928 3 128 3 80 6 208 12 123 9 376 21 499 21 848 19 787 40 1,635
1隊 151 (47 人) 198 人
2隊 1隊 372 5 (51 人) (24 人) 423 人 29 人
0 1 1隊 4 (24 人) 1隊 0 (5 人) 7隊 707 (221 人) 928 人

37. In this problem as shown on the right, each square represents a digit from 0 to 9. What is the final product? Answer: ___________. 38. For some integer n, the sum of all of the digits of n is a multiple of 8 and the sum of all of the digits of n + 1 is also a multiple of 8. If n <= 2015, what is the greatest possible value of n? Answer: ___________. 39. In triangle ABC on the right, BD:DC = 1:2. If the area of triangle ABP is 7 and the area of triangle ACP is 5, what is the area of triangle ADP? 2 0 1 5 A P
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1. 2 × 0 + 1 × 4 – 2 × 0 + 1 × 5 = ( ) A) 0 B) 5 C) 9 D) 15 2. There are 84 beavers in a colony. Yesterday they all went out in teams of 6 to collect logs. Today they are all going out in teams of 4. There will be ? more teams today than there were yesterday. ( ) A) 2 B) 7 C) 14 D) 21 3. 12 345 + 54 321 = 11 111 × ? A) 66 666 B) 666 ( ) C) 66 D) 6 ? years mmon multiple of 22, 42, 62, 82, and 102 is ( ) A) 3840 B) 14 400 C) 57 600 D) 230 400 28. A snail crawls 2400 mm per hour. It takes ? seconds to crawl 1 mm. ( ) 1 2 A) B) C) 1.5 D) 3 3 3 29. A circle can intersect a quadrilateral at ? points. ( ) A) 0, 2 or 8 only B) 0, 2, 4, 6 or 8 only C) 1, 2, 3, 4, 6, or 8 only D) 0, 1, 2, 3, 4, 5, 6, 7, or 8 30. Carla loves shells! She collects them, labelling each with a 1-, 2-, or 3-letter code. If the same letters are used in a different order, it is a different code. She has used every such code, so she has ? shells. ( ) A) 156 B) 17 576 C) 18 278 D) 20 888 31. If the sum of 50 consecutive integers is 1525, what is the sum of the next 50 consecutive integers? ( ) A) 1575 B) 2775 C) 4025 D) 76 250 32. Of 4 pairs of twins, 3 students are chosen to do a report together. There are ? possible groups of 3 that don’t include both twins from a pair. ( ) A) 16 B) 24 C) 28 D) 32 33. 八年后我的年龄是两年前我的年龄的两倍。请问两年后我是几岁？ ( ) A) 14 B) 16 C) 18 D) 20 34. 将 0.75 转换为分数，这些分数的分子和分母都是小于 100 的正整数。这样的分数共有 多少个？ ( ) A) 3 B) 24 C) 25 D) 33 35. 船长们划船 5 个小时。从第二个小时开始，每个小时行驶的距离比 前一个小时少了 2 千米。如果 5 个小时的平均行驶速度是 6 千米/小时，那么前 2 个小时行驶了多少千米？ ( ) A) 6 B) 12 C) 16 D) 18 二、填空题(每小题 5 分，答对加 5 分，答错不扣分，共 25 分) 36. Calculate the number of digits which are equal to 0 in the product of 826446281, 11 and 11. Answer: ___________.

2017年美国“数学大联盟杯赛”初赛四年级试卷2016-2017年度美国“数学大联盟杯赛”(中国赛区)初赛(四年级)(初赛时间：2016年11月20日，考试时间90分钟，总分200分)学生诚信协议：考试期间，我确定没有就所涉及的问题或结论，与任何人、用任何方式交流或讨论，我确定以下的答案均为我个人独立完成的成果，否则愿接受本次成绩无效的处罚。

如果您同意遵守以上协议请在装订线内签名选择题：每小题5分，答对加5分，答错不扣分，共200分，答案请填涂在答题卡上。

1.Which of the following is the greatest?A) 2.017 B) 20.17 C) 201.7 D) 20172.The sum of the degree-measures of the interior angles of a triangle isA) 180 B) 360 C) 540 D) 7203.100 + 200 + 300 + 400 + 500 = 300 ×?A) 3 B) 4 C) 5 D) 64.100 ÷ 4 = 200 ÷?A) 2 B) 4 C) 8 D) 165.In tonight’s talent show, Jack sang 3 songs. The number of songs that Jill sang is 8 lessthan 4 times the number of songs Jack sang. How many songs did Jill sing?A) 3 B) 4 C) 6 D) 76.Doubling a certain number is the same as adding that number and 36. What is thatnumber?A) 18 B) 36 C) 54 D) 727.The side-lengths of three square farms are 1 km, 2 km, and 3 km respectively. The sum ofthe areas of these three farms is ? km2.A) 6 B) 12 C) 13 D) 148.What is the greatest common factor of 2017 and 20 × 17?A) 1 B) 2 C) 3 D) 59.If a computer can download 2% of the files in 2 seconds, how many seconds does it taketo download all the files?A) 100 B) 200 C) 300 D) 40010.In yes terday’s giant-pie eating, all pies were the same size. Al ate 3/4 of a giant pie, Barbate 4/5 of a giant pie, Cy ate 5/6 of a giant pie, and Di ate 6/7 of a giant pie. Who ate the largest portion?A) Al B) Barb C) Cy D) Di 11.The product of two consecutive positive integers is alwaysA) odd B) evenC) prime D) composite12.In a 5-term sequence, the first term is 2. The value of each term after the first is twice thatof its previous term. What is the product of the 5 terms?A) 24B) 210C) 215D) 24513.Ace, Bo, and Cat performed in a talent show. Bo’s total score was twice that of Ace, andCat’s total score was three times that of Bo. If the sum of all three total scores was 900, what was Cat’s total score?A) 100 B) 200C) 300 D) 60014.The length of each side of triangle T is an integer. If twosides of T have lengths of 2016and 2017, what is the least possible value for the length of the third side?A) 1 B) 2 C) 4032 D) 403315.If the sum of three consecutive whole numbers is 2016, what is the sum of the next threeconsecutive whole numbers?A) 2032 B) 2025 C) 2020 D) 201716.If the sum of a prime and a composite is 2017, what is the least possible value for theproduct of the two numbers?A) 3000 B) 4030 C) 6042 D) 912017.What is the smallest whole number that leaves a remainder of 2 when divided by each of 3,4, 5, and 6?A) 58 B) 60 C) 62 D) 6418.What is the highest power of 2 that divides 1 × 2 × 3 × 4 × 5 × 6 × 7 × 8 × 9?A) 25B) 26C) 27D) 2819.The product of the digits of 23 is 6. How many different whole numbers between 100 and999 have a product of 6?A) 12 B) 9 C) 6 D) 320.What is the value of 1% of 10% of 100%?A) 0.001 B) 0.01 C) 0.1 D) 121.In a box that contains only balls that are red, yellow, or green, 10% of the balls are red, 1/5of the balls are yellow, and 49 balls are green. How many balls are in the box?A) 70 B) 80 C) 90 D) 10022.Of the following, which has the greatest number of positive whole number divisors?A) 24 B) 26 C) 51 D) 2017第1页，共4页第2页，共4页23.If you subtract the sum of the digits of a whole numbergreater than 9 from the numberitself, the result must be divisible byA) 5 B) 6 C) 9 D) 1224.I bought a painting for $40, sold it for $50, rebought it for $60, and resold it for $70. Mytotal profit on the 4 transactions wasA) $10 B) $20 C) $30 D) $4025.What is the minimum number of whole number divisors of the product of two differentcomposite numbers?A) 5 B) 6 C) 8 D) 926.For each whole number from 1000 to 9999, inclusive, I write the product of its digits.How many of the products I write are even?A) 625 B) 3125 C) 5775 D) 837527.Lisa baked some cookies and cakes. Baking one cookie requires 4 cups of sugar and 3cups of flour, and baking one cake requires 7 cups of sugar and 5 cups of flour. At the end she used 83 cups of sugar and 61 cups of flour. How many cookies did she bake?A) 11 B) 12 C) 13 D) 1428.Working by oneself, Al can build a bridge in 3 years, Barb can build a bridge in 4 years,and Cy can build a bridge in 5 years. Working together, how long, in years, does it take them to build the bridge?A) 12B)6047C)6053D) 129.Jack is a gifted athlete who has trained hardfor the Olympic marathon. In the lasthundred yards he finds the inner strength toincrease his pace and overtakes the runner inthe second place.But then, with the finishing line just feetaway, he is overt aken by two other runners…What medal will Jack receive?A) Gold B) SilverC) Bronze D) None30.If we juxtapose three congruent squares, we get a rectangle with perimeter 64. What is thearea of one of the squares?A) 36 B) 49 C) 64 D) 8131.In a four-digit perfect square, the digits in the hundreds and thousands places are equal,and the digits in the tens and ones places are equal. What is this number?A) 6644 B) 7744 C) 8844 D) 9944 32.For how many of the integers from 100 to 999 inclusive is the product of its digits equal to9?A) 6 B) 7 C) 8 D) 933.What is the smallest positive integer x for which (x + 8) is divisible by 5 and (x + 17) isdivisible by 7?A) 30 B) 31 C) 32 D) 3334.Tom’s new tower was completed. The total value ofthe project, the sum of the cost of the construction andthe cost of the land, was one million dollars. The cost of the construction was $900,000 more than the cost of theland. So what did T om pay for the land?A) $25,000 B) $50,000C) $75,000 D) $90,00035.五个连续正整数的和总是可以被下面哪个数整除？A) 2 B) 3 C) 5 D) 736.从1开始，鲍勃一共喊了2017个数，从第一个数之后的每个数都比前一个数大4。

第六届“走进每秒的数学花园”中国青少年数学论坛趣味数学解题技能展示大赛初赛小学六年级试卷一、填空题I(每题8分，共40分)1. 11111111 612203042567290+++++++=解：原式=11111111223349102105-+-++-=-=L L2．一个表面积为56emz的长方体如图切成27个小长方体，这27个小长方体表面积的和是______cm2．解：每一刀增加两个切面，增加的表面积等于与切面平行的两个表面积,所以每个方向切两刀后，表面积增加到原来的3倍，即表面积的和为168cm2.3．将2、4、6、8、12、18、24、36、72填人右边的九宫格，使每行每列及两条对角线上三数的积都相等．每行的三个数的积是______．解：每行三个数的积相等，所以这个积的3次方等于9个数的积，这就个数是：2130、2230、2131、2330、2231、2132、2331、2232、2332，它们的积21839，所以每行上的3个数的积为2633=1728. 4.0.2.0080.A BCC A B••••=，三位数ABC的最大值是多少？解析：2.008化为分数是251125，可以约分为251125的分数有502250、753375，所以ABC的最大值为753.5． 如图所示，长方形ABCD 内的阴影部分的面积之和为70，AB=8,AD=15四边形EFGO 的面积为______．分析：根据容斥关系：四边形EFGO 的面积=三角形AFC+三角形DBF-白色部分的面积 三角形AFC+三角形DBF=长方形面积的一半即60，白色部分的面积等于长方形面积减去阴影部分的面积，即120-70=50 所以四边形的面积=60-50=10二、填空题Ⅱ(每题l0分，共50分)6． 如图，ABCD 是正方形．阴影部分的面积为_______．（π取3．14）分析：正方形和它的内切圆的面积比是固定的，即4：π.小正方形的面积等于（3+5）2-4×3×5÷2==34，所以其内切圆的面积等于34÷4×（4-π）=7.317． 用数字l ～8各一个组成8位数，使得任意相邻三个数字组成的三位数都是3的倍数．共有种组成方法．分析：l ～8中被三除余1和余2的数各有3个，被3整除的数有两个，根据题目条件可以推导，符合条件的排列，一定符合“被三除所得余数以3位周期”，所以8个数字，第1、4、7位上的数被3除同余，第2、5、8位上的数被3除同余，第3、6位上的数被3除同余，显然第3、6位上的数被3整除，第1、4、7位上的数被3除可以余1也可以余2，第2、5、8位上的数被3除可以余2可以余1，余数的安排上共有2种方法，余数安排定后，还有同余数之间的排列，一共有3！×3！×2！=144种方法.8．N 为自然数，且1+N ，2+N 、……、9+N 与690都有大于l 的公约数．N 的最小值为_______．解析：690=2×3×5×23，连续9个数中，最多有5个是2的倍数，也有可能有4个是2的倍数，如果有5个连续奇数，这5个连续奇数中最多有2个3的倍数，1个5的倍数，1个23的倍数，所以必然有一个数不是2、3、5、23的倍数，即与690没有大于l 的公约数.所以9个数中只有4个奇数，剩下的5个数，有3个3的倍数，1个5的倍数，1个23的倍数，则1+N 、3N +、5N +、7N +、9N +是偶数，剩下的4个数中2+N 、8N +是3的倍数（5各偶数当中只有5N +是3的倍数），还有4N +、6N +一个是5的倍数，一个是23的倍数.剩下的可以用中国剩余定理求解，5N +是2和3的倍数，且相邻两个数中一个是23的倍数，另一个是5的倍数，显然524N +=是最小解，所以N 的最小值为19.9． 50位同学围成一圈，从某同学开始顺时针报数．第一位同学报l ，跳过一人第 三位同学报2，跳过两人第六位同学报3，……这样下去，报到2008为止．报2008的同学第一次报的是_______．分析：将这些学生按报数方向依次编号；1、2、3、……49、50、51……2008，每一个人的编号不唯一，例如编号为2001、1951……101、51的和编号为1的为同一个人，这样第n 次报数的人的编号为()12n n +, 报2008的同学的编号为2017036，他的最小编号为36，我们知道36=1+2+3+4+5+6+7+8，所以报2008的同学第一次报8.10．用l —9填满三角形空格，一个格子只能填人一个数字，使每个数字在每一行，每一列(包括不相连的行，列)及每个粗黑线围成的区域中至多出现一次．分析：解题顺序如第二附图，依照A 、B 、C 、D ……的顺序.三、填空题Ⅲ(每题l2分，共60分)11．A 、B 两杯食盐水各有40克，浓度比是 3：2．在B 中加入60克水，然后倒人A 中________克．再在A 、B 中加人水，使它们均为100克，这时浓度比为7：3．分析：在B中加入60克水后，B盐水浓度减少为原来的25，但溶质质量不变，此时两杯盐水的盐质量比仍然为3：2，B中的盐占所有盐的质量的22325=+，但最终状态B中的盐占所有盐的质量的337310=+，也就是说B中的盐减少了32111054-÷=，也就是说从A中倒出了14的盐水，即25克.12．中午l2时，校准A、B、C三钟．当天下午A钟6点时，B钟5点50分；B钟7点时，C钟7点20分．晚上C钟11点时，A钟_____点_____分，B钟_______点_____分．分析：下午A钟6点，B钟5点50分，两钟的运行比为360：350=36：35B钟7点时，C钟7点20分，时钟运行比为420：440=21：22，A:B:C=108:105:110所以C钟11点的时候，A钟10：48，B钟10：30.13．一次，齐王与大将田忌赛马．每人有四匹马，分为四等．田忌知道齐王这次比赛马的出场顺序依次为一等，二等，三等，四等，而且还知道这八匹马跑的最快的是齐王的一等马，接着依次为自己的一等，齐王的二等，自己的二等，齐王的三等，自己的三等，齐王的四等，自己的四等．田忌有______种方法安排自己的马的出场顺序，保证自己至少能赢两场比赛．分析：枚举法，枚举出所有方法：1423、2143、2413、3124、3142、3412、3421、4123、4132、4231、4312、4321.14．机器人A、B从P出发到Q，将Q处的球搬到P点．A每次搬3个，往返一次需l5秒．8每次搬5个，往返一次需25秒．竞赛开始8立即出发，A在B后10秒出发．在竞赛开始后的420秒内，A领先的时间是_______秒，B领先的时间是______秒．(领先指搬到P的球多)．分析：对俩机器人的工作情况分别ABA-B:时间0- 25- 40- 50- 55- 70- 75- 85- 100- 115 ……个数差0 -2 1 -4 -1 2 -3 0 -2 1 ……所以从25秒开始，每隔75秒就会出现一个循环，即周期为75秒.前25秒，A、B都没有完成搬运。

B) Monday
C) Tuesday
D) Friday
12. Rounding a decimal to the nearest whole number yields a number that is at most ? greater than the original decimal.
A) 0.05
B) 0.1
C) 0.5
D) 0.9
13. The perimeter of a rectangle with area 2019 and integral side-lengths is greatest when its length and width diffC) 670
A) 6
B) 9
C) 12
D) 18
3. The number 36 is the product of -6 and
A) -6
B) 6
C) -30
D) 42
4. 20 ×18 = 20 ×19 + 20 × ?
A) -1
B) 0
C) 1
D) 20
5. Angel arrived 3 of an hour early for her noon appointment. At what time did Angel 10
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2017-2018年度美国“数学大联盟杯赛”(中国赛区)初赛(三年级)(初赛时间：2017年11月26日，考试时间90分钟，总分200分)学生诚信协议：考试期间，我确定没有就所涉及的问题或结论，与任何人、用任何方式交流或讨论，我确定我所填写的答案均为我个人独立完成的成果，否则愿接受本次成绩无效的处罚。

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1. 5 + 6 + 7 + 1825 + 175 =A) 2015 B) 2016 C) 2017 D) 20182.The sum of 2018 and ? is an even number.A) 222 B) 223 C) 225 D) 2273.John and Jill have $92 in total. John has three times as much money as Jill. How muchmoney does John have?A) $60 B) $63 C) $66 D) $694.Tom is a basketball lover! On his book, he wrote the phrase “ILOVENBA” 100 times.What is the 500th letter he wrote?A) L B) B C) V D) N5.An 8 by 25 rectangle has the same area as a rectangle with dimensionsA) 4 by 50 B) 6 by 25 C) 10 by 22 D) 12 by 156.What is the positive difference between the sum of the first 100 positive integers and thesum of the next 50 positive integers?A) 1000 B) 1225 C) 2025 D) 50507.You have a ten-foot pole that needs to be cut into ten equal pieces. If it takes ten secondsto make each cut, how many seconds will the job take?A) 110 B) 100 C) 95 D) 908.Amy rounded 2018 to the nearest tens. Ben rounded 2018 to the nearest hundreds. Thesum of their two numbers isA) 4000 B) 4016 C) 4020 D) 4040 9.Which of the following pairs of numbers has the greatest least common multiple?A) 5,6 B) 6,8 C) 8,12 D) 10,2010.For every 2 pencils Dan bought, he also bought 5 pens. If he bought 10 pencils, how manypens did he buy?A) 25 B) 50 C) 10 D) 1311.Twenty days after Thursday isA) Monday B) Tuesday C) Wednesday D) Thursday12.Of the following, ? angle has the least degree-measure.A) an obtuse B) an acute C) a right D) a straight13.Every student in my class shouted out a whole number in turn. The number the firststudent shouted out was 1. Then each student after the first shouted out a number that is 3 more than the number the previous student did. Which number below is a possible number shouted out by one of the students?A) 101 B) 102 C) 103 D) 10414.A boy bought a baseball and a bat, paying $1.25 for both items. If the ball cost 25 centsmore than the bat, how much did the ball cost?A) $1.00 B) $0.75 C) $0.55 D) $0.5015.2 hours + ? minutes + 40 seconds = 7600 secondsA) 5 B) 6 C) 10 D) 3016.In the figure on the right, please put digits 1-7 in the sevencircles so that the three digits in every straight line add upto 12. What is the digit in the middle circle?A) 3 B) 4 C) 5 D) 617.If 5 adults ate 20 apples each and 3 children ate 12 apples in total, what is the averagenumber of apples that each person ate?A) 12 B) 14 C) 15 D) 1618.What is the perimeter of the figure on the right? Note: Allinterior angles in the figure are right angles or 270°.A) 100 B) 110C) 120 D) 16019.Thirty people are waiting in line to buy pizza. There are 10 peoplein front of Andy. Susan is the last person in the line. How manypeople are between Andy and Susan?A) 18 B) 19C) 20 D) 2120.Thirty-nine hours after 9:00 AM isA) 1:00 AM B) 12:00 PM C) 8:00 PM D) 12:00 AM21.200 + 400 + 600 + 800 = (1 + 2 + 3 + 4) ×?A) 2 B) 20 C) 200 D) 200022.11…11 (the number consisting of 2016 1’s) is not a mult iple ofA) 11 B) 111 C) 1111 D) 1111123.The average of two thousands and two millions isA) 10000 B) 1000000 C) 1001000 D) 111100024.A triangle has the same area as a square. If the length of a base of the triangle is the sameas the side-length of the square, and the height of the triangle to the base is 4, what is thearea of the square?A) 1/2 B) 2 C) 4 D) 825.When V olta found a field in the shape of an isosceles triangle, she was soexcited that she ran a lap around all three sides. Two sides of the field havelengths of 505 m each, and the third side has a whole-number length.What is the greatest possible distance that V olta might have run in one lap?A) 2016 B) 2017 C) 2018 D) 201926.25 ×66 = 75 ×?A) 22 B) 44 C) 16 D) 3327.The number that has an odd number of whole number divisors isA) 15 B) 16 C) 17 D) 1828.In a sequence of 8 numbers, the average of the 8 terms is 15. If the average of the firstthree terms is 16 and the average of the next two terms is 15, what is the average of thelast three terms?A) 12 B) 13 C) 14 D) 1529.All years between 2000 and 2050 that are divisible by 4 are leap years.No other years between 2000 and 2050 are leap years. How many daysare there all together in the 17 years from 2010 to 2026?A) 6029 B) 6030 C) 5018 D) 501930.The sum of the hundreds digit and the tens digit of 2357 isA) 5 B) 8 C) 10 D) 1231.Which of the expressions below has the greatest value of (quotient × remainder)?A) 27 ÷ 4 B) 47 ÷ 6C) 57 ÷ 8 D) 87 ÷ 1232.I have some dimes and nickels, and together these coins are worth $3. If I replace everynickel with a quarter, I will have $5. How many dimes do I have?A) 10 B) 15 C) 20 D) 2533.I am a lovely cat. When I multiply the digits of a whole numberand the product I get is 9, I put that whole number on my list offavorite numbers. Of the whole numbers from 1000 to 9999, howmany would I put on my list of favorite numbers?A) 5 B) 10 C) 15 D) 2034.The sum of the tens digit and the units digit of the sum 1 + 12 + 123 + 12345+ … + 123456789 isA) 4 B) 5 C) 6 D) 735.The product of all prime numbers between 1 and 10 isA) 210 B) 105C) 1890 D) none of the above36.What is the average of 12, 14, 16, and 18?A) 13 B) 14 C) 15 D) 1637.When Jon shouts out a whole number, Al shouts out the product ofits digits, Barb shouts out the product of the digits of the number Alshouted out, and Cy shouts out the product of the digits of thenumber Barb shouted out. When Cy shouts out 18, what numbermight Jon have shouted out?A) 789 B) 799 C) 899 D) 99938.Each big box contains 3 medium boxes, each medium box contains2 small boxes, and each small box contains 5 apples. How many bigboxes are necessary for 1200 apples?A) 30 B) 40 C) 50 D) 6039.Eighteen years from now, my age will be 4 more than twice my currentage. My age now isA) 12 B) 14 C) 16 D) 1840.Each time Wanda waved her wand, 4 more stars appeared on herdress (which started with no stars). After several waves, Wandamultiplied the total number of stars then on her dress by thenumber of times she had waved her wand. This product cannot beA) 144 B) 256 C) 364 D) 676。

美国“数学大联盟杯赛”(中国赛区)初赛常用英文词汇$美元符号Aacute 锐角的add 计算…总和/加，做加法addition 加，加法adjacent angle 邻角adjacent 邻近的altitude (尤指海拔)高度A.M. 上午amount 数量angle 角arc 弧，弓形area 范围，区域，面积arithmetic 算术，算法arithmetic sequence 等差数列arrangement 排列assume 假定average 平均，平均数/平均的Bbag 袋子base 底billion 十亿/十亿的bisector 二等分线，平分线blond 白肤金发碧眼的Ccalculate 计算calculation 计算capacity 容量cent 美分center 中心/中央的centimeter 厘米circular 圆形的circle 圆周，圆circumference 圆周column 列common 共通的, 公约的congruent 全等的constant 常数/不变的coordinate 坐标corner 角count 数，计算/计数，计算cousin 堂[表]兄弟，堂[表]姊妹crate 箱子cross 交叉的cube 立方体，立方cubic 立方体的，立方的cylindrical 圆柱的Ddecimal 十进制的，小数的/小数define 定义degree 度数denominator 分母determine 确定diagonal 对角线的，对角线diagram 图表diameter 直径diamond 菱形difference 差额digit 阿拉伯数字dime (美元)十美分dimension 尺寸divide 除division 除法divisor 除数，约数dollar (符号为$) 美元double 两倍/使加倍Eeight 八，第八eighteen 十八的，十八个的equal 相等的/等于equation 方程式，等式equilateral 等边的/等边形equivalent 相等的，相当的/相等estimate 估计evaluate 估计，求…的值even 偶数的/偶数example 例子，例题expansion 展开express 表达，表示expression 式，表达式，符号exterior 外部的Fface 表面factor因子，因数female 女的，雌性的fifteen 十五fifth 第五的figure 圆形find 得到first 首先，第一/第一的five 五，五个formula 公式forklift 铲车four 四，四个fraction 分数function 函数Ggeometrical 几何学的，几何的geometric sequence 等比数列graph 图表greatest common divisor 最大公约数，最大公因子Hhalf 一半/一半的hectare 公顷(等于1万平方米) height 高度，海拔hexagon 六角形，六边形horizontal 水平的how 多少，多么hundred 百，百个hyperbola 双曲线hypotenuse 直角三角形之斜边Iinequality 不等式infinite 无限的，无数的inscribe 使内切integer 整数interior 内部的intersect 相交，交叉intersection 交集，交叉点isosceles等腰三角形Kkilometer 千米，公里Lleast common multiple 最小公倍数length 长度less 少的，小的lift 举起，使升起，提起，抬起line segment 线段line 直线liter 公升Mmale 男的，雄性的map 地图，图mark 记号，符号，标记mass 质量mathematics 数学maximum 最大量/最大极限的mean 平均的/平均数measure 测量meter 米，公尺midpoint 中点，正中央million 百万，百万个minimum 最小的，最低的mixed number 带分数multiply 乘Nnatural number 自然数negative 负数/负的nickel (美元)五美分nine 九，九个ninety 九十number 数，数字numerator 分子numerical 数字的，用数表示的Ooctagon 八边形，八角形odd 奇数的one 一，一个operation 运算Pparabola 抛物线parallel 平行的parallelogram 平行四边形penny 一美分pentagon 五角形，五边形per 每一percent 百分比，百分数percentage 百分比,百分数,百分率perfect cube 完全立方perfect square 完全平方perimeter 周长，周界perpendicular 垂直的，正交的plus 加上P.M. 下午point 点，分数polygon 多变形，多角形polynomial 多项式positive 正的prime 质数prism 棱柱probability 概率product 乘积proportion 比例pyramid 角锥，棱锥Qquadrilateral 四边形quarter 四分之一，二十五(美分) quotient 商Rradius半径ratio 比，比率real number 实数reciprocal 倒数，倒数的rectangle长方形，矩形rectangular矩形的，成直角的region 区域regular 等边的remainder 余数rhombus 菱形，斜方形right 直角的root根rotation 旋转，轮转，循环row 行Ssatisfy 满足scale 比例second 秒/第二sector 扇形segment 段semi 半sequence 数学sequence 数列，序列series 连续，系列，级数seven 七，七个seventh 第七shape 外形side 边sign 符号simplify 简化six 六，六个size 大小，尺寸slope 斜率solid 立体solution 解答，解决sphere 球，球体，范围square root 平方根square 正方形straight 直的subtract 减去，减subtraction 减少sum 总和suppose 假设surface 表面surface area 表面积symmetric 对称性的Tten 十，十个tenth 第十，十分之一term 项third 第三，三分之一thousand 一千，一千个three 三time 次，度，回，倍trapezoid 梯形triangle 三角形tub 桶twelve 十二twenty 二十，二十个two 二，两个tangent 切线，相切的than 与…相比较total 总数/总的triple 三倍数twice 两次，两倍Vvalue 值variable 变数/变量的vertex 顶点vertical 垂直的volume 体积Wwidth 宽度Zzero 零点，零。

2016-2017年度美国“数学大联盟杯赛”（中国赛区）初赛（五年级）1.Which of the has the greatest value?A) 2017 B) 2017C) 20 × 17 D) 20 + 172.Which of the leaves a remainder of 2 when divided by 4?A) 2014 B) 2015 C) 2016 D) 20173.Which of the is a product of two consecutive primes?A) 30 B) 72 C) 77 D) 1874.A Bizz-Number is a integer that either contains the 3 or is a multiple of 3. What is the of the 10th Bizz-Number?A) 24 B) 27 C) 30 D) 315.The of an isosceles triangle with side-lengths 1 and 1008 isA) 1010 B) 1012 C) 2017 D) 20186.How integers less than 2017 are divisible by 16 but not by 4?A) 0 B) 126 C) 378 D) 5047.Jon has a number of pens. If he distributed them evenly among 4 students,he have 3 left. If he distributed them evenly among 5 students, he have 4 left. The minimum number of pens that Jon have isA) 14 B) 17 C) 19 D) 248.Which of the numbers is not divisible by 8?A) 123168 B) 234236 C) 345424 D) 4566249.Which of the is both a square and a cube?A) 36 × 58B) 36 × 59C) 36 × 512D) 39 × 51210.The of two prime numbers cannot beA) odd B) even C) prime D) composite11.At the end of day, the amount of water in a cup is twice what it was atthe beginning of the day. If the cup is at the end of 2017th day, then it was1/4 at the end of the ? day.A) 504th B) 505th C) 2015th D) 2016th12.The grades on an exam are 5, 4, 3, 2, or 1. In a class of 200 students, 1/10of got 5’s, 1/5 of got 4’s, 25% of got 3’s, and 15% of got 2’s. How many students got 1’s?A) 40 B) 60 C) 80 D) 10013.22000 × 52017 = 102000 × ?A) 517B) 51000C) 52000D) 5201714.1% of 1/10 of 10000 is ? percent than 10A) 0 B) 9 C) 90 D) 90015.What is the of the of Circle C to the of Square S if the of adiameter of C and a of S are equal?A) π:1 B) π:2 C) π:3 D) π:416.Which of the is not a prime?A) 2003 B) 2011 C) 2017 D) 201917.If the sum of prime numbers is 30, what is the possible value of any of the primes?A) 19 B) 23 C) 27 D) 2918.For $3 I spend on books, I spend $4 on and $5 on toys. If I spent $20 on food, how much, in dollars, did I spend in total?A) 60 B) 90 C) 120 D) 15019.How positive odd factors does 25 × 35 × 55 have?A) 25 B) 36 C) 125 D) 21620.The of scalene triangles with perimeter 15 and side-lengths isA) 3 B) 5 C) 6 D) 721.Which of the when rounding to the nearest thousands, hundreds, and tens, 3000, 3500, and 3460, respectively?A) 3210 B) 3333 C) 3456 D) 351722.Which of the below has exactly 5 positive divisors?A) 16 B) 49 C) 64 D) 10023.Each after the 1st in the sequence 1, 5, 9, … is 4 than the previousterm. The greatest in sequence that is < 1000 and that leaves a of1 when divided by 6 isA) 991 B) 995 C) 997 D) 99924.For integer from 100 to 999 I the of the integer’s digits. Howmany of the products I are prime?A) 4 B) 8 C) 12 D) 1625.If a machine paints at a of 1 m2/sec, its is alsoA) 600 cm2/min B) 6000 cm2/minC) 60000 cm2/min D) 600000 cm2/min26.The of Square A is 1. The of Square B is times ofSquare A. The of Square C is times of Square B. The of Square C is ? times of Square A.A) 3 B) 6 C) 36 D) 8127.If the 17 minutes ago was 19:43, what will be the 17 minutes from now?A) 20:00 B) 20:17 C) 20:34 D) 20:1528.Pick any greater than 100 and subtract the sum of its from theinteger. The largest that must the result isA) 1 B) 3 C) 9 D) 2729.The number of needed in a room so there are always atleast five in the room born in the same month isA) 48 B) 49 C) 60 D) 6130.If M, A, T, and H are digits such that MATH + HTAM = 12221, is the value of M + A + T + H?A) 8 B) 20 C) 22 D) 2431.If 10 forks, 20 knives, and 30 $360, and 30 forks, 20 knives, and10 $240, what is the of 5 forks, 5 knives, and 5 spoons?A) 15 B) 75 C) 150 D) 22532.Write, in reduced form, the value ofA) 0.5 B) 1 C) 1.5 D) 233.Al, Barb, Cal, Di, Ed, Fred, and participated in a chess tournament. Eachplayer play each of his six opponents exactly once. So far, Al has 1match. Barb has 2 matches. Cal has 3 matches. Di has 4matches. Ed has 5 matches, and has 6 matches. How manymatches has at this point?A) 1 B) 3 C) 5 D) 734.What is the number of different integers I can choose from the 100positive integers so that no of these integers could be the of the sides of the same triangle?A) 8 B) 9 C) 10 D) 1135.What is the value of change that you can have in US (pennies, nickels, dimes, and quarters) without being able to someone exact change for a one-dollar bill?A) $0.90 B) $0.99 C) $1.19 D) $1.2936.小罗星期一工作了2个小时。

2017-2018年度美国“数学大联盟杯赛”(中国赛区)初赛(十、十一、十二年级)(初赛时间：2017年11月26日，考试时间90分钟，总分300分)学生诚信协议：考试期间，我确定没有就所涉及的问题或结论，与任何人、用任何方式交流或讨论，我确定我所填写的答案均为我个人独立完成的成果，否则愿接受本次成绩无效的处罚。

请在装订线内签名表示你同意遵守以上规定。

考前注意事项：1. 本试卷是十、十一、十二年级试卷，请确保和你的参赛年级一致；2. 本试卷共4页(正反面都有试题)，请检查是否有空白页，页数是否齐全；3. 请确保你已经拿到以下材料：本试卷(共4页，正反面都有试题)、答题纸、英文词汇手册、草稿纸。

考试完毕，请务必将英文词汇手册带回家，上面有如何查询初赛成绩、及如何参加复赛的说明。

其他材料均不能带走，请留在原地。

填空题(每小题10分，答对加10分，答错不扣分，共300分。

)1.Each pirate wants his own treasure chest, but there is 1 more pirate than thereare treasure chests. If the pirates would agree to pair up so each pirateshares a treasure chest with another pirate, then 1 treasure chest wouldnot be assigned to any pirate. How many treasure chests are there?Answer: ________________.2.If m and nare positive integers that satisfy 10=, what is the greatest possiblevalue of m + n?Answer: ________________.3.There are an infinite number of points with positive coordinates(x,y) the sum of whose coordinates is the square of an integer.Among all such points (x,y), which one satisfies y = 2x and hasx as small as possible?Answer: ________________.4.As shown, a small square is inscribed in one of the triangles formed whenboth diagonals of a larger square are drawn. If the area of the larger squareis 144, what is the area of the smaller square?Answer: ________________.5.Trisection points on opposite sides of a rectangle are joined, as shown. Ifthe area of the shaded region is 2018, what is the area of the rectangle?Answer: ________________.6. A unit fraction is a fraction whose numerator is 1 and whosedenominator is a positive integer. What is the largest rationalnumber that can be written as the sum of 3 different unitfractions?Answer: ________________.7.What is the greatest possible perimeter of a rectangle whose length and width are differentprime numbers, each less than 120?Answer: ________________.8.Mom, Dad, and I each write a positive integer. My number is leastand Dad's is greatest. The average of all 3 numbers is 20. Theaverage of the 2 smallest numbers is 8. If Dad's number is d andif my number is m, what is the greatest possible value of d–m?Answer: ________________.9.If 8 different integers are chosen at random from the first 15 positive integers, what is theprobability that an additional number chosen at random from the remaining 7 positiveintegers is smaller than every one of the 8 originally chosen positive integers?Answer: ________________.10.What sequence of 5 positive integers has these three properties:1) All but one of the numbers is a multiple of 5.2) Every number after the first is 1 more than the sum of all the preceding numbers.3) The first number is as small as possible.Answer: ________________.11.Three beavers (one not shown) take turns biting a tree until it falls. Thesecond beaver is twice as likely as the first to make the tree fall. Thethird is twice as likely as the second to make the tree fall. What isthe probability that a bite taken by the third beaver causes thetree to fall?Answer: ________________.12.What is the ratio, larger to smaller, of a rectangle's dimensions if halfof the rectangle is similar to the original rectangle?Answer: ________________.第1页，共4页第2页，共4页A rectangle is partitioned into 9 different squares, as shown at the right. The area of the smallest square, shown fully darkened, is 1. Two other squares have areas of 196 and 324, as shown. What is the area of the shaded square? Answer: ________________.When the square of an eight-digit integer is subtracted from the square of a differenteight-digit integer, the difference will sometimes have eight identical even digits. What are both possible values of the repeated digit in such a situation? Answer: ________________.If the perimeter of an isosceles triangle with integral sides is 2017, how many different lengthsare possible for the legs? Answer: ________________.What are all ordered triples of positive primes (p ,q ,r ) which satisfy p q + 1 = r ? Answer: ________________.The reflection of (6,3) across the line x = 4 is (2,3). If m ≠ 4, what is the reflection of (m ,n )across the line x = 4? Answer: ________________.The vertices of a triangle are (8,7), (0,1), and (8,1). What are thecoordinates of all points inside this triangle that have integralcoordinates and lie on the bisector of the smallest angle of the triangle? Answer: ________________.In a regular 10-sided polygon, two pairs of different vertices (four different verticesaltogether) are chosen at random, so that all points chosen are distinct from each other. What is the probability that the line segments determined by each pair of points do not intersect? Answer: ________________.A line segment is drawn from the upper right vertex of aparallelogram, as shown, dividing the opposite side into segments with lengths in a 2:1 ratio. If the area of the parallelogram is 90, what is the area of the shaded region?Answer: ________________.21. If 0 < a ≤ b ≤ 1, what is the maximum value of ab 2 – a 2b ? Answer: ________________.22. What are all ordered pairs of integers (x ,y ) that satisfy 5x 3 + 2xy – 23 = 0? Answer: ________________.23. If two altitudes of a triangle have lengths 10 and 15, what is the smallest integer that couldbe the length of the third altitude?Answer: ________________.24. If h is the number of heads obtained when 4 fair coins are each tossed once, what is theexpected (average) value of h 2? Answer: ________________.25. What is the largest integer N for which 7x + 11y = N has no solution in non-negativeintegers (x ,y )? Answer: ________________.26. There are only two six-digit integers n greater than 100 000 for which n 2 has n as its finalsix digits (or, equivalently, for which n 2 – n is divisible by 106). One of the integers is 890 625. What is the other?Answer: ________________.27. A hexagon is inscribed in a circle as shown. If lengths of three sidesof the hexagon are each 1 and the lengths of the other three sides are each 2, what is the area of this hexagon? Write your answer in its exact format or round to the nearest tenth. Answer: ________________.28. If x is a number chosen uniformly at random between 0 and 1, what is the probability thatthe greatest integer ≤ 21log x ⎛⎫⎪⎝⎭ is odd?Answer: ________________.29. In the interval -1 < x < 1, sin θ is one root of x 4 – 4x 3 + 2x 2 – 4x + 1 = 0. In that sameinterval, for what ordered pair of integers (a ,b ) is cos 2θ one root of x 2 + ax + b = 0? Answer: ________________.30. Let P (x ) = 2x 10 + 3x 9 + 4x + 9. If z is a non-real solution of z 3 = 1, what is the numericalvalue of 23111P P P z z z ⎛⎫⎛⎫⎛⎫++ ⎪ ⎪ ⎪⎝⎭⎝⎭⎝⎭?Answer: ________________.第3页，共4页第4页，共4页。

A) 100
B) 160
C) 200
D) 250
二、填空题(每小题 5 分，答对加 5 分，答错不扣分，共 50 分，答案请填涂在答题卡上)
31. The sum of the digits of 2014 is 2 + 0 + 1 + 4 = 7. Let n be a natural number.
m = n + 2014. The sum of the digits of m is half the sum of the digits of n.
What is the minimum value of n?
Answer: ______.
32. The sum of 5 different prime numbers is 200. Each of the 5 prime
1
2
26. If 5 of the 200 stripes on Frank’s giant shell are blue, 5 of the remaining
stripes are brown, and the rest are white, there are ? more white stripes
D) 110
22. The average of 2014 sixes is equal to the average of 4028 ? .
A) threes
B) sixes
C) nines
D) twelves
23. What is 0.625% of 8% of 500?
A) 0.25
B) 2.5
数字为三个连续的偶数，个位数字为三个连续的奇数。如果将四位数的

2013-2014 年度美国“数学大联盟杯赛”(中国赛区)初赛答案
(五、六级) 一、 选择题 1. C. The band’s trombone plays 2013 notes, the trumpet plays 2014 notes, and the tuba plays 218 notes. That is a total of 2013 + 2014 + 218 = 4245 notes. A) 6245 B) 6045 C) 4245 D) 645 2. B. This has the same remainder as 1 divided by 3. The remainder is 1. A) 0 B) 1 C) 2 D) 3 3. A. 20 − 5 C) 25 D) 30 4. D. (2 × 2) × (2 × 3) × (2 × 4) × (2 × 5) = 2 × 3 × 4 × 5 × (2 × 2 × 2 × 2). A) 2 B) 6 C) 8 D) 16 5. A. When I split the cost of a video game equally with 4 friends, we each pay $12. It costs the five of us 5 × $12 = $60. If only 4 of us split the cost, we each pay $60 ÷ 4 = $15. We each pay $15 − $12 = $3 more. A) $3.00 B) $4.00 C) $15.00 D) $16.00 6. C. At 5:00 P.M. on Friday, Hal got locked in. Since 5040 mins. is 5040 ÷60 = 84 hrs., Hal got out in 3 days 12 hrs. That’s Tuesday at 5 A.M. A) Sunday B) Monday C) Tuesday D) Wednesday

美国数学大联盟杯∙美国“数学大联盟杯赛”分为初赛，复赛，决赛三个层次。

初赛，复赛均在国内进行，采用美国大联盟杯赛原题（与美国同时同题）加上中国组委会命题的挑战题。

初赛采用在线考试方式，优秀者进入复赛，复赛为纸质试题。

复赛的优胜者进入决赛并，决赛在美国斯坦福大学举行，同时在那里参加为期5天的数学夏令营。

三年级的数学竞赛试题采用美国“数学大联盟杯赛”试题(一级)，加上组委会命题的挑战题。

竞赛时间为60分钟。

全部采用选择题或填空题(共40题)，总分200分。

其中40%的题目翻译成中文，其余60%为英文原题。

学生可以携带正规出版社出版的纸质简明英汉数学字典。

(禁止携带任何电子版的英汉字典、电子词典或计算器等。

)∙四年级的数学竞赛试题采用美国“数学大联盟杯赛”试题(二级)，加上组委会命题的挑战题。

竞赛时间为60分钟。

全部采用选择题或填空题(共40题)，总分200分。

其中30%的题目翻译成中文，其余70%为英文原题。

学生可以携带正规出版社出版的纸质简明英汉数学字典。

(禁止携带任何电子版的英汉字典、电子词典或计算器等。

)∙五年级的数学竞赛试题采用美国“数学大联盟杯赛”试题(三级)，加上组委会命题的挑战题。

竞赛时间为90分钟。

全部采用选择题或填空题(共50题)，总分250分。

其中20%的题目翻译成中文，其余80%为英文原题。

学生可以携带正规出版社出版的纸质简明英汉数学字典。

(禁止携带任何电子版的英汉字典、电子词典或计算器等。

)∙六年级、七年级(初一)的竞赛采用美国“数学大联盟杯赛”试题(四级)，加上组委会命题的挑战题。

竞赛时间为90分钟。

全部采用选择题或填空题(共50题)，总分250分。

所有题目英文命题。

学生可以携带正规出版社出版的纸质简明英汉数学字典。

(禁止携带任何电子版的英汉字典、电子词典或计算器等。

)∙初二、初三的竞赛采用美国“数学大联盟杯赛”试题(五级)，加上组委会命题的挑战题。

竞赛时间为120分钟。

全部采用选择题或填空题(共60题)，总分300分。

2017-2018年度美国“数学大联盟杯赛”(中国赛区)初赛(六年级)(初赛时间：2017年11月26日，考试时间90分钟，总分200分)学生诚信协议：考试期间，我确定没有就所涉及的问题或结论，与任何人、用任何方式交流或讨论， 我确定我所填写的答案均为我个人独立完成的成果，否则愿接受本次成绩无效的处罚。

请在装订线内签名表示你同意遵守以上规定。

考前注意事项：1. 本试卷是六年级试卷，请确保和你的参赛年级一致；2. 本试卷共4页(正反面都有试题)，请检查是否有空白页，页数是否齐全；3. 请确保你已经拿到以下材料：本试卷(共4页，正反面都有试题)、答题卡、答题卡使用说明、英文词汇手册、 草稿纸。

考试完毕，请务必将英文词汇手册带回家，上面有如何查询初赛成绩、 及如何参加复赛的说明。

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1. Pick any integer greater than 1. Double it twice, then triple the result. The final outcomeis ? of your starting integer.A) 700%B) 1100%C) 1200%D) 1300%2. Barry listened to the radio for 3 hours and 36 minutes. Rounded to thenearest 10 minutes, for how many minutes was Barry listening? A) 210 B) 220 C) 330 D) 340 3. Divide 99 by 22 to get a quotient and remainder. Divide that remainder by that quotient, and the new remainder is A) 4 B) 3 C) 2 D) 14. A man had five pieces of chain, each made up of three links, figure below. He wanted to join the five pieces together to make a big chain of fifteen links and went to a blacksmith to see how much it would cost. “Well,” said the blacksmith, “I will charge you 50 cents for cutting a link and $1.00 for welding a link. Any bending that is required is free.” Given those prices, what is the smallest amount of money for which the job could be done? Note: In a chain, each link is connected to one or two other links. A) $4.50 B) $5.00 C) $5.50 D) $6.00 5. A bee sat on the head of a horse rider whose horse was trotting eastbound at a steady five miles per hour. Some distance ahead on the same path, another horse and rider were approaching westbound, also at five miles per hour. When the two horses were 20 miles apart, the bee left the first horse rider and flew toward the second horse at a rate of ten miles per hour. Upon reaching the second horse, the bee immediately turned around and flew back at the same rate to the first horse. If the bee kept up this performance until the two riders met, how far (in miles) did he travel from the moment he left the first horse rider?A) 10B) 20C) 30D) None of the above6. Which of the following is the sum of the prime factors of 2018?A) 11 B) 219 C) 1011 D) 20197. If the length of the longest side of a triangle is 18, which of the following could not be the length of its second-longest side? A) 9 B) 10 C) 12 D) 17 8. My final score in a competition is the average of my scores on 5 rounds. To get a final score of 88 after getting 84, 80, and 92 on the first 3 rounds, what must be my average score for the last 2 rounds? A) 88 B) 90 C) 92 D) 96 9. Mr. Rice had breakfast one day at a restaurant with Mr. Wheat. When it came time to pay the bill, it was found that Mr. Rice had as many one-dollar bills as Mr. Wheat had quarters. (Mr. Rice had one-dollar bills only, and Mr. Wheat had quarters only.) Rather than each man paying separately, Mr. Rice paid his share of the bill, $6, to Mr. Wheat. At that point, Mr. Wheat had four times as much money as Mr. Rice. How much money did Mr. Rice have at the beginning? A) $6 B) $8 C) $9 D) $12 10. Professor Peach teaches chemistry to clever kids. The ratio of freshmen to other students in his class is 3:8. The total number of students in Professor Peach’s class could be A) 42 B) 45 C) 56 D) 77 11. 440 ÷ 220 = A) 22B) 24C) 220D) 26012. Mr. Bogsworth once left a will which read:To Bob, twice as much as to Betty. To Brian, twice as much as to Bob. To Bill, twice as much as to Brian.If his estate was valued at $45000, how much money did Betty, one of his four heirs, receive? A) $1000 B) $2000 C) $3000 D) $6000 13. I paid $5 and got 5 quarters, 5 dimes, and 5 nickels in change. I spent A) $3.00 B) $3.25 C) $3.45 D) $3.75 14. One side of Todd ’s truck is a perfect rectangle with an area of 12 m 2. If its length is 3 times its width, then its perimeter is A) 8 m B) 12 m C) 16 m D) 20 m15. If a bird in the hand is worth two in the bush, and a bird in the bush is worth four in the sky, then 4 birds in the hand are worth ? birds in the sky.A) 1B) 4C) 16D) 3216. On each of the four shelves of my bookcase is a different prime number of books. Therecould be a total of ? books on my shelves.A) 15B) 21C) 22D) 24第1页，共4页 第2页，共4页Seven years ago I realized that my age would be tripled twelve years from then. How old am I now? A) 11 B) 13 C) 16 D) 18How many fractions with a numerator of 1 and a whole-number denominator are greater than 0.01 and less than 1? A) 98 B) 99 C) 100 D) 101If I write the letters R-E-P-E-A-T repeatedly, stopping when I have written exactly 100 letters, how many times do I write the letter E? A) 16 B) 18 C) 32 D) 34On my map, 1 cm represents 100 km. If a park shown on the map is a rectangle that is2.5 cm by 4 cm, the area of the actual park is ? km 2. A) 100 B) 1000 C) 10 000 D) 100 000Gloomy Gus’s Tu esday rain cloud shows up every Tuesday at 8:30 A.M.and every 50 minutes after that. Its last appearance on Tuesday is at ? P.M.A) 11:00 B) 11:10 C) 11:30 D) 11:50If my lucky number divided by its reciprocal is 100, then the square ofmy lucky number isA) 100 B) 10 C) 1D) 1100A boy and his sister were walking down the street one afternoon when they met a kind old man. When the old man asked them about the size of their family, the boy quicklyanswered. “I have as many brothers as I have sisters,” he proudly stated. Not to be left out, the girl added, “I have three times as many brothers as I have sisters.” Can you tell how many boys and girls in total there were in their family? A) 5 B) 6 C) 7 D) 8A farmer was asked how many pigs he had. “Well,” he said, “if I had just as m any more again, plus half as many more, plus another 1.5 times more, I would have three dozen.” How many pigs did he have?A) 6 B) 9 C) 12 D) 15 15% of 80 is 40% ofA) 30B) 55C) 105D) 210It took me 90 minutes to cycle 45 km to the beach. Later I got a ride from the beach tothe park at twice my cycling speed. If the ride to the park took 15 minutes, what distance did I travel from the beach to the park?A) 15 kmB) 30 kmC) 45 kmD) 135 kmTed, Rick, and Sam painted a wall together. Ted painted 80% more ofthe wall than Sam painted. Sam painted 40% less than Rick. Ted painted ? of the amount that Rick painted. A) 102% B) 108% C) 120% D) 140% The greatest integer power of 20 that is a divisor of 5050 isA) 2020B) 2025C) 2050D) 2012529. The ones digit of the sum of all even integers from 2 to 1492 is A) 2B) 4 C) 8 D) 030. The median of 12, 13, 14, 15, 16, and 17isA) 18 B) 223840 C) 514 D) 94031. The average of all positive even integers from 2 to 2018 is A) 1000 B) 1009 C) 1010 D) 1014 32. Pirate Percy has 300 coins in his chest. Of the Spanish coins,20% are gold. If 100 of the coins are gold but not Spanish and 70 of the coins are neither gold nor Spanish, how many Spanish gold coins are in Percy’s chest?A) 20 B) 26 C) 30 D) 3433. When I divided the population of my city by the number of streets in the city, I got a remainder of 18. If the exact quotient on my calculator was 123.06, how many streets are there in my city? A) 60 B) 120 C) 186 D) 30034. What is the greatest number of 3-by-7 rectangles that can be placed inside an 80-by-90 rectangle with no overlapping?A) 312B) 330C) 334D) 34235. How many four-digit whole numbers have four different even digitsand a ones digit greater than its thousands digit?A) 36B) 54C) 60D) 9036. Both arcs AB and AD are quarter circles of radius 5, figure on the right.Arc BCD is a semi-circle of radius 5. What is the area of the region ABCD ? A) 25 B) 10 + 5π C) 50 D) 50 + 5π 37. In the figure on the right, the side-length of the smaller square is 4. The four arcs are four semi-circles. Each side of square ABCD is tangent to one of the semi-circles. The area of ABCD is A) 32 B) 36 C) 48 D) 6438. A million is a large number, a “1” followed by 6 zeros. A googol is a large number, a “1” followed by one hundred zeros. Agoogo lplex is a large number, a “1” followed by a googol of zeros. A googolplexian is a large number, a “1” followed by a googolplex of zeros. A googolplexian isA) 1010 B) 1001010 C) 100101010 D) none of the above 39. If the total number of positive integral divisors of n is 12, what is the greatest possibletotal number of positive integral divisors of n 2? A) 23 B) 24 C) 33 D) 4540. Of all the isosceles triangles whose perimeter is 20 and whose side-lengths are integers, what is the length of the base of the triangle with the largest area? A) 2 B) 5 C) 6 D) 8第3页，共4页第4页，共4页。