2016-2017年度美国“数学大联盟杯赛”(中国赛区)初赛(五年级)
美国“数学大联盟杯赛” 中国赛区 初赛五年级试卷
2017-2018年度美国“数学大联盟杯赛”(中国赛区)初赛(五年级)(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. 本试卷是五年级试卷,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。
其他材料均不能带走,请留在原地。
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. The smallest possible sum of two different prime numbers isA) 3B) 4C) 5D) 62. The greatest common factor of two numbers is3. The product of these two numbers mustbe divisible byA) 6 B) 9 C) 12 D) 18 3. The sum of 5 consecutive one-digit integers is at most A) 15 B) 25 C) 35 D) 45 4. How many two-digit multiples of 10 are also multiples of 12?A) 4B) 3C) 2D) 15. I have read exactly13of the total number of chapters in my 120-page book. If each chapter has the same whole number of pages, then the total number of chapters I have left could beA) 16 B) 24 C) 32 D) 50 6. What is the greatest odd factor of 44 × 55 × 66?A) 36 B) 55 C) 35 × 55 D) 36 × 55 7. What is the sum of the factors of the prime number 2017? A) 2016B) 2017C) 2018D) 20198. Lynn ran in 6 times as many races as the number of racesshe won. How many of her 126 races did Lynn not win?A) 21B) 90C) 96D) 1059. The least common multiple of 8 and 12 is the greatest common factor of 120 andA) 80B) 124C) 144D) 18010. January has the greatest possible number of Saturdays when January 1 occurs on any ofthe following days of the week exceptA) Thursday B) Friday C) Saturday D) Sunday 11. The number that is 10% of 1000 is 10 more than 10% ofA) 90B) 100C) 900D) 99012. The sum of 16 fours has the same value as the product of ? fours.A) 2 B) 3 C) 4 D) 16 13. Of the following, which is the sum of two consecutive integers?A) 111 111B) 222 222C) 444 444D) 888 88814. Abe drove for 2 hours at 30 km/hr. and for 3 hours at 50 km/hr. What was Abe’s averagespeed over the 5 hours?A) 35 km/hr.B) 40 km/hr.C) 42 km/hr.D) 45 km/hr.15. My broken watch runs twice as fast as it should. If my watch first broke at 6:15 P.M.,what time was displayed on my watch 65 minutes later?A) 7:20 P.M. B) 7:25 P.M.C) 8:20 P.M. D) 8:25 P.M.16. (2018 × 2017) + (2018 × 1) =A) 20172 B) 20182 C) 20183D) (2018 + 2017)217. A prized bird lays 2, 3, or 4 eggs each day. If the bird laid 17 eggs in 1 week,on at most how many days that week did the bird lay exactly 2 eggs?A) 2B) 3C) 4D) 518. Of the following, which could be the perimeter of a rectangle whoseside-lengths, in cm, are prime numbers?A) 10 cmB) 22 cmC) 34 cmD) 58 cm19. The average of all possible total values of a 4-coin stack of nickels and dimes (containingat least one of each coin) isA) 20¢B) 30¢C) 40¢D) 60¢20. The diameter of Ann’s drum i s 40 cm more than the radius. What is half the circumference of the drum?A) 120π cmB) 80π cmC) 60π cmD) 40π cm21. Of the following, which expression has the greatest number offactors that are multiples of 2018?A) 2018 × 12B) 20182C) 20192D) 20192019第1页,共4页 第2页,共4页22. When the sum of the factors of a prime number is divided by that prime number, theremainder isA) 0 B) 1 C) 2 D) 3 23. What is the sum of the digits of the greatest integer that has a square root less than 100? A) 18B) 36C) 99D) 10024. My favorite number has 6 different factors. If the product of all 6 factors is 123, what isthe sum of the factors of my favorite number?A) 24B) 28C) 32D) 3625. For how many different pairs of unequal positive integers less than 10 is the least commonmultiple of the numbers less than their product?A) 6B) 7C) 8D) 926. Exactly 12 of the students in my class have at least one brother, and 12 have at least onesister. If 13have no siblings, what fraction of the students in my class have at least onebrother and at least one sister?A) 16 B) 15 C) 14 D) 1327. Each day, Sal swims a lap 1 second faster than on the daybefore. If Sal swims a lap in 60 minutes on the 1st day, on what day does he swim a lap in 10% less time than the 1st day?A) 359th B) 360th C) 361st D) 362nd 28. 20172018 × 20172019 = 2017 ? × 20171009A) 1010B) 2010C) 3028D) 403829. 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) 50D) 50 + 5π30. For every $5 I earn from my job, I save $2. For every $4 I save from my job, I am givenan additional $1 from my parents to add to my savings. How much must I earn in order to have $40 in savings?A) $160B) $120C) $100D) $8031. In the figure on the right, the side-length of the smaller squareis 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 isA) 32B) 36C) 48D) 6432. A million is a large number, a “1” follo wed by 6 zeros. A googol is a large number, a “1”followed by one hundred zeros. A googolplex is a large number, a “1” followed by a googol of zeros. A googolplexian is a large number, a “1” fo llowed by a googolplex of zeros. A googolplexian isA) 10100 B) 1001010C) 100101010D) None of the above33. An integral triangle is a triangle with positive integral side-lengths and a positive area.Such a triangle can have a perimeter as small as 3. What is the next smallest possible perimeter of an integral triangle?A) 4B) 5C) 6D) 734. 2 liter of 2% fat milk + 3 liter of 3% fat milk = 5 liter of ? fat milkA) 2.5%B) 2.6%C) 5%D) 6%35. One day, a motorist came to a hill that was ten-mile drive up one side and a ten-mile drivedown the other. He drove up the hill at an average speed of 30 miles per hour. How fast will he have to drive down the other side to average 60 miles per hour for the entire 20-mile distance?A) 30 miles per hour B) 60 miles per hour C) 90 miles per hour D) None of the above 36. What is the weight of a fish if it weighs ten pounds plus half its weight?A) 10B) 15C) 20D) 2537. Without using pennies, how many different combinations of coins (nickels, dimes,quarters) will make 30 cents?A) 3B) 4C) 5D) 638. A man once bought a fine suit for which he paid $30 more than14of its price. How much did he pay for the suit? A) $30B) $35C) $40D) $4539. A father is five times as old as his son. In fifteen years he will be only twice as old. Howold is the father at present?A) 40B) 35C) 30D) 2540. It takes 30 minutes to completely fill a tank. If, however, a hole allows13of the water that is entering the tank to escape, how long will it then take to fill the tank?A) 40 B) 45 C) 60 D) 90第3页,共4页第4页,共4页。
2017年世界青少年奥林匹克数学竞赛(中国区)选拔赛五年级数学决赛试卷
第1页 共四页 第2页 共四页秘密★启用前世界青少年奥林匹克数学竞赛(中国区)选拔赛全国总决赛试卷注意事项: 1、考生按要求用黑色、蓝色圆珠笔或钢笔在密封线内填好考生的相关信息。
2、考试时间120分钟。
3、本试卷共4页,满分100分。
4、不得在答卷或答题卡上做任何标记。
5、考生超出答题区域答题将不得分。
6、考生在考试期间不得作弊,否则试卷记零分处理。
小学五年级试题一、计算题(每题3分,共12分) 1. 7.1×35+39×3.5-352. (5.6×4.5×8.1)÷(2.8×1.5×2.7)3. 0.7777×0.7+0.1111×2.14. 987654321×123456789-987654320×123456788二、填空题(每空3分,共24分)1. 把一根木头锯成4段需要12分钟,如果锯成8段需要( )分钟。
2. 有三个好朋友,他们的年龄一个比一个大3岁,他们3人年龄数的乘积是3240。
其中最小的年龄是( )岁。
3. 三个不同的自然数的和为2001,它们分别除以19,23,31所得的商相同,所得的余数也相同,这三个数中最大的是( )。
4. 一本书的中间被撕掉了一张,余下的页码数之和正好是907,这本书有( )页。
5. 下列格点中,相邻两个点之间的距离是1cm ,图中三角形的面积是( )平方厘米。
6. 一个最简分数,若分母加上1,分数值是21,若分子加上1,分数值是32,这个分数是( )。
7. 数列1,1,2,3,5,8,13,21…的排列规律是:从第三个数开始,每一个数都是它前面两个数的和,这样的数列叫做斐波拉契数列。
斐波拉契数列的前2017个数中,有( )个偶数。
8. 2008个2008相乘的末位数字是( )。
三、解决问题(每题8分,共64分)1. 图中三角形ABC 的面积是52平方厘米,三角形ABD 与三角形ADC 的面积相等。
美国数学大联盟杯赛五年级试卷(2020新教材)
——教学资料参考参考范本——美国数学大联盟杯赛五年级试卷(2020新教材)______年______月______日____________________部门(初赛时间:2018年11月14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. A 6 by 6 square has the same area as a 4 by ? rectangle.A) 3 B) 6 C) 8 D) 92.Every prime has exactly ? positive divisors.A) 1 B) 2 C) 3 D) 4 or more3.If I answered 34 out of 40 questions on my math testcorrectly, I answered ? % of the questions correctly.A) 75 B) 80 C) 85 D) 904.120 ÷ 3 ÷ 4 × 12 =A) 1 B) 10 C) 12 D) 1205.10 × 20 × 30 × 40 = 24 × ?A) 1000 B) 10 000 C) 100 000 D) 1000 0006.One of my boxes contains 1 pencil and the others each contain 5 pencils. If there are101 pencils in my boxes, how many boxes do I have?A) 19 B) 20 C) 21 D) 227.of those are damaged. How many light bulbs are not damaged?A) 25 B) 504 C) 1512 D) 20xx8.50 × (16 + 24) is the square ofA) -40 B) -4 C) 4 D) 809.Which of the following numbers has exactly 3 positive divisors?A) 49 B) 56 C) 69 D) 10010.Ten people stand in a line. Counting from the left, Jerrystands at the 5th position. Counting from the right, which position is he at?A) 4 B) 5 C) 6 D) 711.On a teamwork project, Jack contributed 2/7 of the totalamount of work, Jill contributed 1/4 of the work, Patcontributed 1/5 of the work, and Matt contributed the rest.第1页,共4页Who contributed the most toward this project?A) Jack B) Jill C) Pat D) Matt12.Which of the following numbers is a factor of 20xx?A) 5 B) 11 C) 48 D) 9913.2 × 4 × 8 × 16 × 32 × 64 =A) 210B) 215C) 221D) 212014.On a game show, Al won four times as much as Bob, and Bobwon four times as much as Cy. If Al won $1536, how much did Al, Bob, and Cy win together?A) $96 B) $384 C) $1920 D) $20xx15. cannot beA) odd B) even C) 11 D) 1716.If a and b are positive integers such that a/b = 5/7, thena +b isA) 12 B) 24 C) 36 D) not able to be determined17.What is the greatest odd factor of the number of hours in all the days of the year 20xx?A) 3 B) 365 C) 1095 D) 328518. If the current month is February, what month will it be 1199 999 months from now?A) January B) February C) March D) April 19. ° less than the other. What is the measure of the larger angle?A) 36°B) 54°C) 63°D) 72°20. (The square root of 16) + (the cube root of 64) + (the 4throot of 256) =A) 12B) 24C) 32D) 6421. In ∆ABC, m ∠A – m ∠B = m ∠B – m ∠C. What is the degreemeasure of ∠B?A) 30B) 60C) 90D) 12022. For every 3 math books I bought, I bought 2 biology books. I bought 55 books in all. How many of those are math books?A) 11 B) 22C) 33D) 4423. ? 1s.A) 17B) 19C) 29D) 3224. Weird Town uses three types of currencies: Cons, Flegs, and Sels. If 3 Sels = 9 Cons and 2 Cons = 4 Flegs, then 5 Sels = ? Flegs.A) 12B) 24 C) 30 D) 3625. If the length of a rectangular prism with volume V isdoubled while the width and the height are halved, the volume of the new prism will beA) 4VB) V /2C) VD) 2V26. Rick and Roy each stands at different ends of a straight road that is 64 m long. They run toward each other. Rick ’s speed is 3 m/s and Roy ’s speed is 5 m/s. They will meet in? seconds.……………线…………………………………………………………… ……………答…………………题………………………………………。
【2020】最新美国数学大联盟杯赛五年级试卷
(初赛时间:2018年11月14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. A 6 by 6 square has the same area as a 4 by ? rectangle.A) 3 B) 6 C) 8 D) 92.Every prime has exactly ? positive divisors.A) 1 B) 2 C) 3 D) 4 or more3.If I answered 34 out of 40 questions on my math test correctly, I answered ? % of the questionscorrectly.A) 75 B) 80 C) 85 D) 904.120 ÷ 3 ÷ 4 × 12 =A) 1 B) 10 C) 12 D) 1205.10 × 20 × 30 × 40 = 24 × ?A) 1000 B) 10 000 C) 100 000 D) 1000 0006.One of my boxes contains 1 pencil and the others each contain 5 pencils. If there are 101 pencils inmy boxes, how many boxes do I have?A) 19 B) 20 C) 21 D) 227.of those are damaged. How many light bulbs are not damaged?A) 25 B) 504 C) 1512 D) 20xx8.50 × (16 + 24) is the square ofA) -40 B) -4 C) 4 D) 809.Which of the following numbers has exactly 3 positive divisors?A) 49 B) 56 C) 69 D) 10010.Ten people stand in a line. Counting from the left, Jerry stands at the 5th position. Counting fromthe right, which position is he at?A) 4 B) 5 C) 6 D) 72 / 4第1页,共4页23. ? 1s.4 Flegs, then5 Sels = ? Flegs.。
上海走美5年级初赛,如果没学过奥数能得多少分
啰里啰嗦写了这么多,只是个人看法,欢迎拍砖。
【上海】沙漏
37+1
19
3
73+1
37
2
145+1
73
1
289+1
145
不成功尝试之一,再尝试把猴王不摘桃的次序上下移,不能得到题目规定的范围值, 因此 385 是唯一答案
第 10 题:长方形内有 2017 个点,连同长方形 4 个顶点,一共 2021 个点,这些点任意 3 个点都不在同一条直线上,以这些点中某 3 个点为顶点,可作出多少个互不重叠的三角 形
第 9 题: 一堆桃子,奇数个且数量大于 360 小于 400。猴王分桃规则是:若桃子偶数个,分桃猴子 分走 1 半,若奇数个,猴王从树上摘一个桃子放入桃堆让分桃猴子分一半,当桃子剩下一 个后停止分桃。第 9 个猴子分桃后剩下一个桃子,猴王一共摘了 7 个桃子放入桃堆,问原 来有多少个桃 个人以为跟高大上的二进制没啥大关系,不用二进制,照样做出来,规则还是找规律。 从最后剩下 1 个桃来看,第 9 个猴子分桃前只能剩下 2 个桃子,如果剩 3 个,则分好后必 然剩下 2 个桃子,进而推出第 8 个猴子分桃前剩下的桃子数可能为 3 或 4,然后列表倒推
第 7 题:从 1、2、3、4、5、6、7、8、9 这 9 个数选出 6 个不同的数,分别写在一个正方 体的 6 个面上,使任意相邻的面所写 2 个数的差不小于 2,这 6 个数之和最小多少?
找规律,1 和 2 对面后不能选 3,45 对面后不能选 6,选 78,得 27
2017年第十五届“走美杯”小数数学竞赛初赛试卷(五年级B卷答案及解析)
2017年第十五届“走美杯”小数数学竞赛初赛试卷(五年级B卷)-学生用卷一、填空题共15题,共120 分1、计算:(写成小数的形式,精确到小数点后三位)。
2、两个标准骰子一起投掷次,点数之和第一次为,第二次为的可能性(概率)为/(先填分子,再填分母)。
3、大于的自然数,如果满足所有因数之和等于它自身的倍,则这样的数称为完美数或完全数。
比如,的所有因数为,,,,,是最小的完美数。
是否有无限多个完美数的问题至今仍然是困扰人类的难题之一。
研究完美数可以从计算自然数的所有因数之和开始,的所有因数之和为。
4、昊宇写好了五封信和五个不同地址的信封,要将每封信放入相应的信封中,一个信封只放入一封信。
只有一封信装对,其余全部被装错的情形有种。
5、“点游戏”是很多人熟悉的数学游戏,游戏过程如下:任意从张扑克牌(不包括大小王)中抽取张,用这张扑克牌上的数字(,,,)通过加减乘除四则运算得出,最先找到算法者获胜。
游戏规定张扑克牌都要用到,而且每张牌只能用次,比如,,,,则可以由算法得到,海亮在一次游戏中抽到了,,,,经过思考,他发现,我们将满足的牌组称为“海亮牌组”,请再写出组不同的“海亮牌组”。
6、在中国古代的历法中,甲、乙、丙、丁、戊、己、庚、辛、壬、癸被称为“十天干”,子、丑、寅、卯、辰、巳、午、未、申、酉、戌、亥叫作“十二地支,;十天干和十二地支进行循环组合:甲子、乙丑、丙寅。
一直到癸亥,共得到个组合,称为六十甲子。
如此周而复始用来纪年的方法,称为甲子纪年法。
在甲子纪年中,以“丑”结尾的年份除了“乙丑”外,还有。
7、现有个抽屉,每个抽屉中都放置个玻璃球(形状大小相同),分别为蓝色、红色与黄色。
如果分别从这个抽屉中各取出一个玻璃球放在一个布袋中,则布袋中的个玻璃球共有种不同情况。
8、古希腊的数学家们将自然数按照以下方式与多边形联系起来,定义了多边形数:比如,根据图示,三边形数:,,,,四边形数:,,,,五边形数:,,,,六边形数:,,,,那么,第个三边形数,四边形数,五边形数,六边形数分别为。
第15届走美杯决赛五年级自测卷(解析版) -
B P 【解析】将 BP 反向延长如下图所示构造弦图,
C
A E B F H G
D
C
P 以 BP 为底,△PAB 的高是 AF,于是有:S△PAB=PB×AF÷2=90,即 AF=15 厘米, 同理有 CG=8 厘米.因此 S□ABCD=152+82=289 平方厘米.
10、有一堆石头,第一次取走一个,第二次取走两个,每次比前一次多一个,如果最后一次 不够则全取。结果发现每次取完后剩余的石头数目都不是质数。当一开始的石头数目在 1000-1100 之间时只有一个值符合,这个值是 。 【考点】质数合数、构造 【答案】1081 【解析】本题考查的是构造的思想,题目中说开始的石头数目在 1000-1100 之间只有一个值 符合,意思就是说只要找到一个符合题意的数其它的数肯定就不符合,也不需要证明。我们 知道连续 n(n≥3)个自然数的和一定是合数(奇数项,中间项是平均数。偶数项,刚好配 对) 。构造 1+2+3+4+……+45+46=1081,检验 1081-1 即为 2+3+4+……+45+46 其结果必为合数,1081-1-2 即为 3+4+5+……+45+46 其结果必为合数,……,1081 -1-2-……-43 即为 44+45+46 其结果必为合数,再减 44 最后的结果为 45+46=91 也 是合数(注:剩最后两数时必须检验,因为 n<3 时不一定是合数) ,所以符合条件的值为 1081。 填空题Ⅲ(每题 12 分,共 60 分) 11、将四个不同的数字排在一起,可以组成 24 个不同的四位数(4×3×2×1=24) 。将这 24 个四位数按从小到大排列顺序排列,第二个是 5 的倍数;按从大到小排列,第二个是不 能被 4 整除的偶数; 按从小到大排列的第五个与第二十个的差在 3000~4000 之间。 请求出这 24 个四位数中最大的一个数是 。 【考点】数的整除 【答案】7543 【解析】设这个四个不同的数字从小到大依次为 A、B、C、D;因为这个四个互不相同的数 字可以组成 4× 3× 2× 1=24 个不同的四位数;所以这个四个数字均不为 0。因为这 24 个四位 数按从小到大排列顺序排列,第二个 ABDC 是 5 的倍数;所以 5|C,C=5; 因为这 24 个四位数按从大到小排列顺序排列,第二个 DCAB 是不能被 4 整除的偶数;所 以 AB 是不能被 4 整除的偶数,因为 A<B<C=5;所以 AB =14 或 34,即 B=4,A=1 或 3; 因为这 24 个四位数按从小到大排列顺序排列,第五个与第二十个的差 DACB ADBC 在 3000~4000 之间;比较百位数字可知 A<D,需从千位借位相减;所以 D-A-1=3,D-A =4;当 A=1 时, D=5,而 C=5,不符合题意;所以 A=3,D=7,这 24 个四位数中 最大的一个 DCBA =7543。
117度—数学科校外比赛奖项
小學數理遊蹤邀請賽(小學六年級組) 小學數理遊蹤邀請賽(小學五年級組) 環亞太杯國際數學邀請賽進階賽(小學四年級) 環亞太杯國際數學邀請賽初賽(小學四年級) 華夏盃全國數學奧林匹克晉級總決賽 華夏盃全國數學奧林匹克晉級總決賽 華夏盃全國數學奧林匹克晉級總決賽 華夏盃全國數學奧林匹克晉級賽(華南賽區) 華夏盃全國數學奧林匹克晉級賽(華南賽區) 華夏盃全國數學奧林匹克晉級賽(華南賽區) 華夏盃全國數學奧林匹克初賽 華夏盃全國數學奧林匹克初賽 華夏盃全國數學奧林匹克初賽 華夏盃全國數學奧林匹克初賽 華夏盃全國數學奧林匹克初賽 COMO 兩岸菁英數學邀請賽初賽 AIMO 港澳盃決賽 AIMO 港澳盃晉級賽 AIMO 港澳盃初賽 全港小學數學比賽(荃灣區) 全港小學數學比賽(荃灣區) 荃灣及葵涌區魔力橋小學邀請賽 香港小學數學奧林匹克比賽 全港少年數多酷大賽總決賽(少年組隊際) 香港盃全港心算比賽(低年級組) 冠軍 優異獎 特等獎 一等獎 一等獎 二等獎 三等獎 一等獎 二等獎 三等獎 一等獎 二等獎 二等獎 三等獎 三等獎 二等獎 銀獎 金獎 金獎 優異獎 優良獎 優異獎 銀獎 優勝獎 冠軍 6B 鄭汶晋、6B 王創宇、6B 李文杰、6B 廖俊豪 5B 吳沛熹、5B 温立勝、5B 鍾心瑀、5B 馬盈慧 4B 陳穎賢 4B 陳穎賢 2D 任曉航 2C 趙逸飛 4A 司徒彩瑩、5A 曾竣瑋、5B 馬盈慧 2D 陳嘉樂、4B 陳穎賢、5B 吳沛熹 2C 趙逸飛、2D 黎穎瞳、5B 溫立勝 2D 任曉航、3A 袁鴻林、3A 陳世康、4A 司徒彩瑩、5B 馬盈慧、5A 曾竣瑋、5A 馮嘉洭 4B 陳穎賢、5B 吳沛熹 2D 任曉航、2D 陳嘉樂、2C 黃皓勤、2C 趙逸飛、2D 黎穎瞳、3A 袁鴻林 5A 曾竣瑋、5B 溫立勝、6B 王創宇、6A 陳守邦、6B 廖俊豪
2015年美国“数学大联盟杯赛”(中国赛区)初赛五年级试卷
2014-2015 年度美国“数学大联盟杯赛”(中国赛区)初赛
(五年级) (初赛时间:2015 年 1 月 3 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。
)
城市
22. The prime factorization of a whole number less than 100 is the product of at most ? primes (not necessarily different). ( ) A) 3 B) 4 C) 5 D) 6 23. A rectangle with sides of integer length is divided into a square region and a shaded rectangular region as shown. If the area of the shaded
11. Thok has a simple plan. He will spend 50% of the day in the cave, 25% of the rest of the day on the hunt, and the remainder of the day watching films outside. How many hours will Thok spend watching films? ( ) A) 3 B) 6 C) 9 D) 25 12. 2 × 3 × 6 × 36 × 2 × 3 × 6 × 36 = A) 65 B) 66 ( C) 67 ) D) 68
20162017年度美国“数学大联盟杯赛”(中国赛区)初赛(五年级).doc
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。
2016-2017年度美国“数学大联盟杯赛”(中国赛区)初赛(五年级)名师制作优质教学资料
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)2017B)2017C)20×17D)20+172.Which of the leaves a remainder of2when divided by4?A)2014B)2015C)2016D)20173.Which of the is a pr oduct of two consecutive primes?A)30B)72C)77D)1874.A Bizz-Number is a integer that either contains the3or is a multiple of3.What is the of the10th Bizz-Number?A)24B)27C)30D)315.The of an isosceles triangle with side-lengths1and1008isA)1010B)1012C)2017D)20186.How integers less than2017are divisible by16bu t not by4?A)0B)126C)378D)5047.Jon has a n u mbe r of pens.If he distributed them evenly among4students, he have3left.If he distributed them evenly among5students,he have 4left.The minimum n u mbe r of pens that Jon have isA)14B)17C)19D)248.Which of the numbers is not divisible by8?A)123168B)234236C)345424D)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 at the beginning of the day.If the cup is at the end of2017th day,then it was1/4at the end of the?day.A)504th B)505th C)2015th D)2016th12.The grades on an exam are5,4,3,2,or1.In a class of200students,1/10of got5’s,1/5of got4’s,25%ofgot3’s,and15%of got2’s.How many students got1’s?A)40B)60C)80D)10013.22000×52017=102000×?A)517B)51000C)52000D)5201714.1%of1/10of10000is?percent than10A)0B)9C)90D)90015.What is the of the of Circle C t o the of Square S if the ofa diameter of C and a of S are equal?A)π:1B)π:2C)π:3D)π:416.Which of the is not a prime?A)2003B)2011C)2017D)201917.If the su m of prime numbers is30,what is the possible value of any of the primes?A)19B)23C)27D)2918.For$3I s pe n d on books,I s pe n d$4on and$5on toys.If I spent$20 on food,how much,in dollars,did I s pen d in total?A)60B)90C)120D)15019.How positive odd factors do e s25×35×55have?A)25B)36C)125D)21620.The of scalene triangles with perimeter15and side-lengths isA)3B)5C)6D)721.Which of the when rounding t o the nearest thousands,hundreds,and tens,3000,3500,and3460,respectively?A)3210B)3333C)3456D)351722.Which of the below has exactly5positive divisors?A)16B)49C)64D)10023.Each after the1st in the sequence1,5,9,…is4than the previous term.The gr eatest in sequence that is<1000and that leavesa of1when divided by6isA)991B)995C)997D)99924.For integer from100t o999I the of the integer’s digits.How many of the products I are prime?A)4B)8C)12D)1625.If a machine paints at a of1m2/sec,its is alsoA)600cm2/min B)6000cm2/minof Square C is timesC)60000cm2/min D)600000cm2/min26.The of Square A is1.The of Square B is times of Square A.The of Square B.The of Square C is?times of Square A.A)3B)6C)36D)8127.If the17minutes ago was19:43,what will be the17minutes from now?A)20:00B)20:17C)20:34D)20:1528.Pick any greater than100and subtract the su m of its from the integer.The largest that must the result isA)1B)3C)9D)2729.The n u mbe r of needed in a room so there are always at least five in the room born in the s ame month isA)48B)49C)60D)6130.If M,A,T,and H are digits such that MA TH+HT AM=12221,is the value of M+A+T+H?A)8B)20C)22D)2431.If10forks,20knives,and30$360,and30forks,20knives,and10$240,what is the of5forks,5knives,and5spoons?A)15B)75C)150D)22532.Write,in r educed form,the value ofA)0.5B)1C)1.5D)233.Al,Barb,Cal,Di,Ed,Fred,and participated in a chess tournament.Each player play each of his six o ppo n en t s exactly once.So far,Al has1 match.Barb has2matches.Cal has3matches.Di has4 matches.Ed hasmatches has5matches,andat this point?has6matches.How many A)1B)3C)5D)7of these integers could be the34. What is the n u mber of different integers I can choose from the100positive integers so that noof the sides ofthe s a me triangle? A) 8 B) 9 C) 10 D) 1135. What is thevalue of change that you can have in US(pennies,nickels, dimes, and quarters) without being able t o someone exact change for aone-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。
(参考资料)2014年美国“数学大联盟杯赛”(中国赛区)初赛五、六年级试卷
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
2020最新美国数学大联盟杯赛五年级试卷
——教学资料参考参考范本——美国数学大联盟杯赛五年级试卷______年______月______日____________________部门(初赛时间:2018年11月14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. A 6 by 6 square has the same area as a 4 by ? rectangle.A) 3 B) 6 C) 8 D) 92.Every prime has exactly ? positive divisors.A) 1 B) 2 C) 3 D) 4 or more3.If I answered 34 out of 40 questions on my math testcorrectly, I answered ? % of the questions correctly.A) 75 B) 80 C) 85 D) 904.120 ÷ 3 ÷ 4 × 12 =A) 1 B) 10 C) 12 D) 1205.10 × 20 × 30 × 40 = 24 × ?A) 1000 B) 10 000 C) 100 000 D) 1000 0006.One of my boxes contains 1 pencil and the others each contain 5 pencils. If there are101 pencils in my boxes, how many boxes do I have?A) 19 B) 20 C) 21 D) 227.of those are damaged. How many light bulbs are not damaged?A) 25 B) 504 C) 1512 D) 20xx8.50 × (16 + 24) is the square ofA) -40 B) -4 C) 4 D) 809.Which of the following numbers has exactly 3 positive divisors?A) 49 B) 56 C) 69 D) 10010.Ten people stand in a line. Counting from the left, Jerrystands at the 5th position. Counting from the right, which position is he at?A) 4 B) 5 C) 6 D) 711.On a teamwork project, Jack contributed 2/7 of the totalamount of work, Jill contributed 1/4 of the work, Patcontributed 1/5 of the work, and Matt contributed the rest.第1页,共4页Who contributed the most toward this project?A) Jack B) Jill C) Pat D) Matt12.Which of the following numbers is a factor of 20xx?A) 5 B) 11 C) 48 D) 9913.2 × 4 × 8 × 16 × 32 × 64 =A) 210B) 215C) 221D) 212014.On a game show, Al won four times as much as Bob, and Bobwon four times as much as Cy. If Al won $1536, how much did Al, Bob, and Cy win together?A) $96 B) $384 C) $1920 D) $20xx15. cannot beA) odd B) even C) 11 D) 1716.If a and b are positive integers such that a/b = 5/7, thena +b isA) 12 B) 24 C) 36 D) not able to be determined17.What is the greatest odd factor of the number of hours in all the days of the year20xx?A) 3 B) 365 C) 1095 D) 328518. If the current month is February, what month will it be 1199 999 months from now?A) January B) February C) March D) April 19. ° less than the other. What is the measure of the larger angle?A) 36°B) 54°C) 63°D) 72°20. (The square root of 16) + (the cube root of 64) + (the 4throot of 256) =A) 12B) 24C) 32D) 6421. In ∆ABC, m ∠A – m ∠B = m ∠B – m ∠C. What is the degreemeasure of ∠B?A) 30B) 60C) 90D) 12022. For every 3 math books I bought, I bought 2 biology books. I bought 55 books in all. How many of those are math books?A) 11 B) 22C) 33D) 4423. 1s.A) 17B) 19C) 29D) 3224. Weird Town uses three types of currencies: Cons, Flegs, and Sels. If 3 Sels = 9 Cons and 2 Cons = 4 Flegs, then 5 Sels = ? Flegs.A) 12B) 24 C) 30 D) 3625. If the length of a rectangular prism with volume V isdoubled while the width and the height are halved, the volume of the new prism will beA) 4VB) V /2C) VD) 2V26. Rick and Roy each stands at different ends of a straight road that is 64 m long. They run toward each other. Rick ’s speed is 3 m/s and Roy ’s speed is 5 m/s. They will meet inseconds.……………线…………………………………………………………… ……………答…………………题………………………………………。
2016年第14届“走美杯”小学数学竞赛试卷(五年级初赛B卷)
2016年第14届“走美杯”小学数学竞赛试卷(五年级初赛B卷)一、填空题Ⅰ(每题8分,共40分)1.(8分)计算:××××××=(写成小数的形式,精确到小数点后两位)2.(8分)1角硬币的正面与反面如图所示,拿三个1角硬币一起投掷一次,得到两个正面一个反面的概率为.3.(8分)大于0的自然数,如果满足所有自然数之和等于它自身的2倍,则这样的数称为完美数或完全数.比如,6的所有因数为1,2,3,4,1+2+3+6=12,6就是最小的完美数.是否有无限个完美数的问题至今仍然是困扰人类的难题之一.研究完美数可以从计算自然数的所有因数之和开始,8128的所有因数之和为.4.(8分)某大型会议上,要从小张、小赵、小李、小罗、小王五名志愿者中选派四人分别从事翻译、导游、礼仪、司机四项不同工作,若其中小张和小赵只能从事前两项工作,其余三人均能从事这四项工作,则不同的选派方案有种.5.(8分)将从1开始到25的连续的自然数相乘,得到1×2×3×…×25,记为25!(读作25的阶乘)用3除25!显然,25!被3整除,得到一个商,再用3除这个商,…,这样一直用3除下去,直到所得的商不能被3整除为止.那么,在这个过程中用3整除了次.二、填空题Ⅱ(每题10分,共50分)6.(10分)如图,已知正方形ABCD中,F是BC边的中点,GC=2DG,E是DF 与BG的交点,四边形ABED的面积与正方形ABCD的比是.7.(10分)如图所示,将一张A4纸沿着长边的2个中点对折,得到2个小长方形,小长方形的长与宽之比与A4纸相同.如果设A4纸的长为29.4厘米,那么,以A4纸的宽为边长的正方形面积为平方厘米(精确到小数点后一位).8.(10分)由一些顶点和边构成的图形称为一个图,对一个图用不同颜色给顶点染色,要求具有相同边的两个顶点染不同的颜色.称为图的点染色,图的点染色通常要研究的问题是完成染色所需要的最少的颜色数,这个数称为图的色数.如图的图称为皮特森图,皮特森图的色数为.9.(10分)在平面上,用边长为1的单位正方形构成正方形网格,顶点都落在单位正方形的顶点(又称为格点)上的简单多边形叫做格点多边形.最简单的格点多边形是格点三角形,而除去三个顶点之外,内部或边上不含格点的格点三角形称为本原格点三角形,如图所示的格点三角形MBN,每一个格点多边形都能够很容易地划分为若干个本原格点三角形.那么,如图中的格点四边形EBGF可以划分为个本原格点三角形.10.(10分)在放置有若干小球的一排木格中,甲乙两人轮流移动小球,移动的规则为:每人每次可以选择某一木格中的任意数目的小球,并将其移动到该木格右边紧邻的那一木格中;当所有小球全部移动到最右端的木格中时,游戏结束,移动最后一个小球的一方获胜.面对如图所示的局面(每个木格中的数字代表小球的数目,木格下方的数字表示木格编号),先手必胜策略,那么,为确保获胜,先手第一步应该移动号木格中的个小球.三、填空题Ⅲ(每题12分,共60分)11.(12分)m,n是两个自然数,满足26019×m﹣649×n=118,那么,m=,n=.12.(12分)以下由1、2构成的无穷数列有个有趣的特征,从第一项开始,把数字相同的项合成一个组,再按照顺序将每组的项数写下来,则这些数构成的无穷数列恰好是它自身.这个数列被称为库拉库斯基数列.按照这个特征,继续写出这个数列后8项(从第14项到第21项),如果已知这个数列的前50项的和为75,第50项为2,则可知道第73项、74项、第75项、第76项分别.13.(12分)不全为零的两个自然数的公因数中的最大者,称作这两个数的最大公因数.如果不全为2个自然数的最大公因数为1,则这两个数称为互素的或互质的,比如.2与3互素.3与8互素;12与15不是互素的.因为它们的最大公因数是3,不超过81的自然数中,有个数与81互素.14.(12分)任何一个直角三角形都有这样的性质:以两个直角边为边长的正方形的面积之和等于以斜边为边长的正方形的面积.这就是著名的勾股定理,在西方又被称为毕达哥拉斯定理.勾般定理有看悠悠4000年的历史,出现了数百个不同的证明.魏晋时期的中国古代数学家刘徽给出了如图1所示的简洁而美妙的证明方法,如图2是以这个方法为基础设计的刘徽模式勾股拼围板刘徽模式勾股拼图板的5个组块,还可以拼成个如图3所示的平行四边形,如果其中的直角三角形直角边分别为3厘米与4厘米,那么,这个平行四边形的周长为厘米15.(12分)在的圆圈中填入1到16的自然数,(每一个只能用一次),连接在同一直线上的4个圆圈中的数字之和都相等,这称为一个8阶幻星图,这个相等的数称为8阶幻星图的和.那么,8阶幻形图的幻和为,并继续完成以下8阶幻星图.2016年第14届“走美杯”小学数学竞赛试卷(五年级初赛B卷)参考答案与试题解析一、填空题Ⅰ(每题8分,共40分)1.(8分)计算:××××××= 1.67(写成小数的形式,精确到小数点后两位)【分析】把分数的分子分母交叉约分,化成最简分数,然后用最简分数的分子除以分母把商保留两位小数即可.【解答】解:××××××===2048÷1225≈1.67故答案为:1.67.【点评】完成本题要注意先约分,再根据分数化小数的方法计算即可.2.(8分)1角硬币的正面与反面如图所示,拿三个1角硬币一起投掷一次,得到两个正面一个反面的概率为.【分析】每个硬币只有正面与反面两种情况,所以拿三个1角硬币一起投掷一次,可能出现••=8种情况,每种两个正面一个反面的概率为×3=;据此解答即可.【解答】解:••=8(种),×3=;答:得到两个正面一个反面的概率为.故答案为:.【点评】本题考查了概率与排列组合知识的灵活应用,关键是求出拿三个1角硬币一起投掷一次,可能出现的情况数.3.(8分)大于0的自然数,如果满足所有自然数之和等于它自身的2倍,则这样的数称为完美数或完全数.比如,6的所有因数为1,2,3,4,1+2+3+6=12,6就是最小的完美数.是否有无限个完美数的问题至今仍然是困扰人类的难题之一.研究完美数可以从计算自然数的所有因数之和开始,8128的所有因数之和为16256.【分析】首先对8128进行分解质因数,计算出因数个数,共14个,找出这7对数字相加即可.【解答】解:分解质因数8128=26×127.8128个因数共有(6+1)×(1+1)=14(个).8128=1×8128=2×4064=4×2032=8×1016=16×508=32×254=64×127.8128的因数和为:1+8128+2+4064+4+2032+8+1016+16+508+32+254+64+127=16256.故答案为:16256.【点评】本题的关键是先进行分解质因数同时计算出8128的因数共有多少个,不重复不遗漏的计算和.成对出现都一起计算比较方便.4.(8分)某大型会议上,要从小张、小赵、小李、小罗、小王五名志愿者中选派四人分别从事翻译、导游、礼仪、司机四项不同工作,若其中小张和小赵只能从事前两项工作,其余三人均能从事这四项工作,则不同的选派方案有36种.【分析】首先考虑特殊情况的两个人,分为不选小张、小赵、小李、小罗、小王5种情况.进行讨论.【解答】解:从5个人中选4人中有①不选小张,小赵有2种选择,剩下3人任意选择,共有3×2×1×2=12种;②不选小赵,小张有2种选择,剩下3人任意选择,共有3×2×1×2=12种;③从小赵,小王,小李选出两个参加共有3种情况.翻译2种,导游1种,礼仪2种,司机1种;共3×2×2=12种;共12+12+12=36种;故答案为:36【点评】排列组合是奥数的重要知识点.注意是5选4的排列.把特殊的对象安排好在进行排列.5.(8分)将从1开始到25的连续的自然数相乘,得到1×2×3×…×25,记为25!(读作25的阶乘)用3除25!显然,25!被3整除,得到一个商,再用3除这个商,…,这样一直用3除下去,直到所得的商不能被3整除为止.那么,在这个过程中用3整除了10次.【分析】被整除多少次就是要看因数3的个数,注意的是9中含有2个3.分别用25除以3,9得到的商的和就是因数3的个数.即可求解.【解答】解:被整除次数就是看因数3的个数.25÷3=8…1和25÷9=2…7.3的倍数有8个,9的倍数有2个,共8+2=10(个).故答案为:10.【点评】此类题中想要找到所有的因数3的个数,需要分别除以3再除以9,因为9的倍数中含有2个3需要再计算一次.以此类推.问题解决.二、填空题Ⅱ(每题10分,共50分)6.(10分)如图,已知正方形ABCD中,F是BC边的中点,GC=2DG,E是DF 与BG的交点,四边形ABED的面积与正方形ABCD的比是5:8.【分析】按题意,作CG的中点H,连接FH,设正方形ABCD的边长为1份,求得△BCG、△DEG的面积所占的份数,再用正方形的面积减去△BCG、△DEG 的面积和,即可得到四边形ABED的面积,不难求出四边形ABED的面积与正方形ABCD的比.【解答】解:如图,作CG 的中点H ,连接FH ,设正方形ABCD 的边长为1份,则:份;份; 又∵S △DEG :S △DFH =1:4,∴份;四边形ABED 的面积=正方形ABCD 的面积﹣S △BGC ﹣S △DEG =1=,即:四边形ABED 的面积与正方形ABCD 的面积的比为:5:8故答案是:5:8.【点评】本题考查了三角形面积,本题突破点是:利用线段之间的比,算出面积比,再用正方形的面积减去三角形的面积即可求得四边形与正方形的面积比.7.(10分)如图所示,将一张A4纸沿着长边的2个中点对折,得到2个小长方形,小长方形的长与宽之比与A4纸相同.如果设A4纸的长为29.4厘米,那么,以A4纸的宽为边长的正方形面积为 432.2 平方厘米(精确到小数点后一位).【分析】根据题意可知原A4纸的长:原A4纸的宽=原A4的宽:原A4纸长的一半,据此比例式可求出原A4纸宽的平方是多少,即是以A4纸的宽为边长的正方形面积.据此解答.【解答】解:设原A4纸的宽是a29.4:a=a :a 2=29.4×a2≈432.2答:以A4纸的宽为边长的正方形面积为432.2平方厘米.故答案为:432.2.【点评】本题的重点是根据小长方形的长与宽之比与A4纸相同,列出比例式进行解答.8.(10分)由一些顶点和边构成的图形称为一个图,对一个图用不同颜色给顶点染色,要求具有相同边的两个顶点染不同的颜色.称为图的点染色,图的点染色通常要研究的问题是完成染色所需要的最少的颜色数,这个数称为图的色数.如图的图称为皮特森图,皮特森图的色数为3.【分析】首先分析五点染色的需求最少是3个颜色,3色可以染外边的五点,枚举即可.【解答】解:依题意可知:因为是5个点循环,数字1和2循环最后还缺一个颜色.染色顺序如图所示:每一个数字代表一个颜色.故答案为:3【点评】本题考查对染色问题的理解和分析,重点是循环的五点至少需要3个颜色.问题解决.9.(10分)在平面上,用边长为1的单位正方形构成正方形网格,顶点都落在单位正方形的顶点(又称为格点)上的简单多边形叫做格点多边形.最简单的格点多边形是格点三角形,而除去三个顶点之外,内部或边上不含格点的格点三角形称为本原格点三角形,如图所示的格点三角形MBN,每一个格点多边形都能够很容易地划分为若干个本原格点三角形.那么,如图中的格点四边形EBGF可以划分为36个本原格点三角形.【分析】这题根据毕克定理S=2×N+L﹣2即可求出这个图能分成多少个本原格点三角形,其中N表示内部的格点数,L表示边界上的格点数.【解答】解:内部格点有15个,边界格点有8个15×2+8﹣2=36故此题填36.【点评】此题属于格点问题,遇到这类问题直接运用公式即可,在运用公式时一定要分清是正方形格点问题还是三角形格点问题,以免公式运用错误.10.(10分)在放置有若干小球的一排木格中,甲乙两人轮流移动小球,移动的规则为:每人每次可以选择某一木格中的任意数目的小球,并将其移动到该木格右边紧邻的那一木格中;当所有小球全部移动到最右端的木格中时,游戏结束,移动最后一个小球的一方获胜.面对如图所示的局面(每个木格中的数字代表小球的数目,木格下方的数字表示木格编号),先手必胜策略,那么,为确保获胜,先手第一步应该移动1号木格中的2个小球.【分析】由题意可知,这个游戏的题的策略是奇数性的利用,由图可知,3号格和1号格里的球数不相同,要确保获胜,先手必须先要取成3号格和1号格里的球数相同,所以先手必须将1号格中的2个小球移入0号格,后手无论怎么移,都会导致这两格球数不一样,先手只须保持两格一样即可最后获胜;据此解答即可.【解答】解:由图可知,3号格和1号格里的球数不相同,要确保获胜,先手必须先要取成3号格和1号格里的球数相同,所以先手必须将1号格中的2个小球移入0号格,后手无论怎么移,都会导致这两格球数不一样,先手只须保持两格一样即可最后获胜.所以为确保获胜,先手第一步应该移动1号木格中的2个小球.故答案为:1,2.【点评】解答此题要明确:先手必须先要取成3号格和1号格里的球数相同才能获胜.三、填空题Ⅲ(每题12分,共60分)11.(12分)m,n是两个自然数,满足26019×m﹣649×n=118,那么,m=2+11×t,n=80+441×t.【分析】要想找到m和n的关系需要将原式中的数字化简,首先分解质因数再进行枚举法找规律即可.【解答】解:分解质因数649=11×59,26019=441×59,118=2×59原式=441m﹣11n=2①当m=1时,441m﹣11n最小的数字是1,不满足条件.②当m=2时,n=80是满足条件的.③当m=3时,441m﹣11n最小可以等于3不满足条件.④当m=4时,441m﹣11n最小可以得4.不满足条件.发现倍数增加一倍得数最小增加1.那么需要让得数等于2增加的数字需要是11的倍数.⑤当m=2+11时,n=80+441⑥当n=2+22时,n=80+882…那么当m=2+11t时(t=0,1,2,3,…),n=80+441t(t=0,1,2,3,…)故当m=2+11t时,n=80+441t.【点评】本题的关键是找到m和n的关系,中间利用字母t转换,找到数字变化的规律表示出来.问题解决.12.(12分)以下由1、2构成的无穷数列有个有趣的特征,从第一项开始,把数字相同的项合成一个组,再按照顺序将每组的项数写下来,则这些数构成的无穷数列恰好是它自身.这个数列被称为库拉库斯基数列.按照这个特征,继续写出这个数列后8项12112212(从第14项到第21项),如果已知这个数列的前50项的和为75,第50项为2,则可知道第73项、74项、第75项、第76项分别1221.【分析】把两列数列上下写成两排,前一问可以根据规律填出:122112122122112112212…,可得从第14项到第21项;如果前50项全部为1,则和应该是50,现在和为75,说明有25个2,每个2意味着上面一列多一个数,现在有25个,说明第50个数2对应的数字是上排第74,75个,所以第73项、74项、第75项、第76项,形如abba,再确定奇偶性和第一个不同,第一个是1,所以74,75个数字为2,所以第73项、74项、第75项、第76项为1221.【解答】解:把两列数列上下写成两排,前一问可以根据规律填出:122112122122112112212…所以从第14项到第21项是12112212;如果前50项全部为1,则和应该是50,现在和为75,说明有25个2,每个2意味着上面一列多一个数,现在有25个,说明第50个数2对应的数字是上排第74,75个,所以第73项、74项、第75项、第76项,形如abba,因为下排每增加一个数字,意味着上排对应数字改变一次奇偶性,如下排第二个数字为2,对应上排数字从1变成2,下排第二个数字2,对应上排数字改变为1,…,以此类推,下排第50个,意味着对应数字改变了49次奇偶性,所以奇偶性和第一个不同,第一个是1,所以74,75个数字为2,所以第73项、74项、第75项、第76项为1221.故答案为12112212;1221.【点评】本题考查奇偶性问题,考查学生规律的寻找,考查学生分析解决问题的能力,属于中档题.13.(12分)不全为零的两个自然数的公因数中的最大者,称作这两个数的最大公因数.如果不全为2个自然数的最大公因数为1,则这两个数称为互素的或互质的,比如.2与3互素.3与8互素;12与15不是互素的.因为它们的最大公因数是3,不超过81的自然数中,有54个数与81互素.【分析】在81个数字中,找到不是互质的,其余就是互质的.所有3的倍数都不是与81互质,不超过81的意思是可以取到81,3的倍数是不符合题意的.【解答】解:在不超过81的数字中3的倍数有81÷3=27(个).在不超过81的数字中有27是和81有最大公约数大于1的数.互质的共有81﹣27=54(个)故答案为:54【点评】此题是逆向思维,要找到互质的,首先找到不互质的更为容易,特别注意1和81也是互质的.所以不需要讨论.14.(12分)任何一个直角三角形都有这样的性质:以两个直角边为边长的正方形的面积之和等于以斜边为边长的正方形的面积.这就是著名的勾股定理,在西方又被称为毕达哥拉斯定理.勾般定理有看悠悠4000年的历史,出现了数百个不同的证明.魏晋时期的中国古代数学家刘徽给出了如图1所示的简洁而美妙的证明方法,如图2是以这个方法为基础设计的刘徽模式勾股拼围板刘徽模式勾股拼图板的5个组块,还可以拼成个如图3所示的平行四边形,如果其中的直角三角形直角边分别为3厘米与4厘米,那么,这个平行四边形的周长为厘米【分析】直角边为3和4的那么斜边长为5,在根据这个平行四边形的面积是不变的,高为4时求出一边即可求出周长.【解答】解:依题意可知:这个图形的面积是32+42=25(平方厘米),斜边长为5.再根据最后的平行四边形的面积是底乘高.在高位4时,底边长为:25÷4=(厘米)周长为:=(厘米)故答案为:【点评】本题的关键是根据面积相当求出当高为4时候的底边长,根据勾股定理知道斜边为5,边长相加既是周长.问题解决.15.(12分)在的圆圈中填入1到16的自然数,(每一个只能用一次),连接在同一直线上的4个圆圈中的数字之和都相等,这称为一个8阶幻星图,这个相等的数称为8阶幻星图的和.那么,8阶幻形图的幻和为34,并继续完成以下8阶幻星图.【分析】8条线的幻和相加就是把所有的数字加了2遍.根据幻和的8倍就是所有数字和的2倍即可求解.【解答】解:根据所有的数字和的两倍就是幻和的8倍可得:1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16=136.136×2=272,272÷8=34.首先根据幻和为34,34﹣2﹣4=28,那么28=16+12唯一情况.在接下来根据数字规律进行分析即可.故答案为:34【点评】本题的关键问题是所有的数字和的2倍等于每一条线的幻和相加.问题解决.。
美国数学大联盟杯
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。
美国数学大联盟杯赛五年级试卷
2015-2016年度美国“数学大联盟杯赛”(中国赛区)初赛(五年级)(初赛时间:2015年11月14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. A 6 by 6 square has the same area as a 4 by ? rectangle.A) 3 B) 6 C) 8 D) 9 2. Every prime has exactly ? positive divisors.A) 1B) 2C) 3D) 4 or more3. If I answered 34 out of 40 questions on my math test correctly, I answered ? % of the questions correctly.A) 75B) 80 C) 85 D) 904. 120 ÷ 3 ÷ 4 × 12 =A) 1 B) 10 C) 12 D) 120 5. 10 × 20 × 30 × 40 = 24 × ?A) 1000B) 10 000C) 100 000D) 1000 0006. One of my boxes contains 1 pencil and the others each contain 5 pencils. If there are 101 pencils in my boxes, how many boxes do I have?A) 19B) 20C) 21D) 227. An electrical company imports 2016 light bulbs. Unfortunately, 25% of those are damaged. How many light bulbs are not damaged?A) 25 B) 504 C) 1512 D) 2016 8. 50 × (16 + 24) is the square ofA) -40 B) -4 C) 4 D) 80 9. Which of the following numbers has exactly 3 positive divisors?A) 49B) 56C) 69D) 10010. Ten people stand in a line. Counting from the left, Jerry stands at the 5th position. Counting from the right, which position is he at?A) 4B) 5C) 6D) 711. On a teamwork project, Jack contributed 2/7 of the total amount of work, Jill contributed 1/4 of the work, Pat contributed 1/5 of the work, and Matt contributed the rest. Who contributed the most toward this project?A) Jack B) Jill C) Pat D) Matt 12. Which of the following numbers is a factor of 2016? A) 5 B) 11 C) 48 D) 99 13. 2 × 4 × 8 × 16 × 32 × 64 =A) 210B) 215C) 221D) 212014. On a game show, Al won four times as much as Bob, and Bob won four times as much as Cy. If Al won $1536, how much did Al, Bob, and Cy win together?A) $96 B) $384 C) $1920 D) $2016 15. The sum of two composites cannot beA) odd B) even C) 11 D) 1716. If a and b are positive integers such that a /b = 5/7, then a + b isA) 12 B) 24 C) 36 D) not able to be determined 17. What is the greatest odd factor of the number of hours in all the days of the year 2015? A) 3B) 365 C) 1095 D) 3285 18. If the current month is February, what month will it be 1 199 999 months from now?A) JanuaryB) FebruaryC) MarchD) April19. Two angles are complementary. One of these angles is 36° less than the other. What is the measure of the larger angle?A) 36° B) 54° C) 63° D) 72° 20. (The square root of 16) + (the cube root of 64) + (the 4th root of 256) = A) 12 B) 24 C) 32 D) 64 21. In ∆ABC , m ∠A – m ∠B = m ∠B – m ∠C . What is the degree measure of ∠B ?A) 30B) 60C) 90D) 12022. For every 3 math books I bought, I bought 2 biology books. I bought 55 books in all. How many of those are math books?A) 11B) 22C) 33D) 4423. John wrote a number whose digits consists entirely of 1s. This number was a composite number. His number could contain exactly ? 1s.A) 17B) 19C) 29D) 3224. Weird Town uses three types of currencies: Cons, Flegs, and Sels. If 3 Sels = 9 Cons and 2 Cons = 4 Flegs, then 5 Sels = ? Flegs.A) 12 B) 24 C) 30 D) 3625. If the length of a rectangular prism with volume V is doubled while the width and the height are halved, the volume of the new prism will be第1页,共4页A) 4V B) V/2 C) V D) 2V26.Rick and Roy each stands at different ends of a straight road that is 64 m long. They runtoward each other. Rick’s speed is 3 m/s and Roy’s speed is 5 m/s. They will meet in? seconds.A) 1 B) 2 C) 4 D) 827.If the area of a certain circle is 2016, its radius isA) sqrt(2016/π) B) sqrt(4032/π)C) 2016/πD) 1008/π28.In a toy shop, the cost of a Teddy Bear is 200% as much as that of a toy train. The cost ofa toy train is 6/5 the cost of a pack of the wooden blocks. The cost of a pack of woodenblocks is $50. What is the cost, in dollars, of the Teddy Bear?A) 60 B) 100 C) 120 D) 20029.In the sequence 2016, 225, 141, 66, 432, 99, 1458 …, each term after the first term is thesum of the cubes of the digits of the previous term. What is the 100th term of thissequence?A) 153 B) 351 C) 370 D) 37130.What is the sum of all the positive divisors of 210?A) 210 – 1 B) 211 – 1 C) 212 – 1 D) 213 – 131.It takes 4 hours for Mike and Lucy to finish a task. It takes Lucy and Jerry 5 hours tofinish the same task. And it takes 6 hours for Mike and Jerry to finish the same task. Lucy and Jerry first work on the task for 1 hour and 45 minutes. Then Mike takes over the task on his own. How many more hours does it take for Mike to finish the task?A) 3 B) 4 C) 5 D) 632.If you sell a cloth at its current price, you get $40 profit. The total profit you get selling 10clothes at 70% of its current price is equal to the total profit you get selling 20 clothes at $82 per cloth. What is the current price of a cloth?A) 80 B) 100 C) 120 D) 12533.There are 6 identical squares in the figure on the right. The side length of eachsquare is 1. Of all the triangles constructed by connecting three of the 18vertices in the figure, how many of them are triangles whose area is 2 andwhich has at least one vertical or horizontal side?A) 12 B) 16 C) 24 D) 2834.Pick up N numbers from 1 to 2015 inclusively, such that the sum of any three of the Nnumbers is divisible by 24. What is the maximum value of N?A) 83 B) 84 C) 168 D) 25235.汤姆有一件花了64美金买来的衬衫,他打算以比原价高出25%的价格出售,他会卖出多少钱?A) $16 B) $32 C) $48 D) $8036.满足以下条件的最小整数是多少:“除以3余2,除以5余4,除以7余6。
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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 have4 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 at the 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,1/10 of 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 ofa diameter 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 previous term. The greatest in sequence that is < 1000 and that leavesa of 1 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. How many 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 the integer. 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 at least 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. Each player play each of his six opponents exactly once. So far, Al has 1 match. Barb has 2 matches. Cal has 3 matches. Di has 4 matches. 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 100 positive 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。