美国国际袋鼠数学竞赛试题

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袋鼠数学数学竞赛试题

袋鼠数学数学竞赛试题
题目，在一个房间里，有一只袋鼠和一只狗。

袋鼠的身高是狗的1/4，袋鼠的体重是狗的1/2。

如果袋鼠的体重增加了20%，那么袋鼠的身高将增加多少？
解答：
1. 利用代数方法解答：
设狗的身高为h，袋鼠的身高为1/4h。

袋鼠的体重为w，狗的体重为2w。

根据题意可得，袋鼠的体重增加20%，即原体重的1.2倍，即1.2w。

设袋鼠身高增加后的身高为x，则有，x = 1/4h + Δh（Δh为身高增加的值）。

根据题意可得，1.2w = 2w (x/h)^3（袋鼠体重的增加与身高的关系）。

整理方程得，(x/h)^3 = 0.6。

解方程可得，x/h ≈ 0.843。

因此，袋鼠的身高增加约为84.3%。

2. 利用比例方法解答：
根据题意可得，袋鼠的身高与狗的身高的比例为1:4，袋鼠的体重与狗的体重的比例为1:2。

设袋鼠的身高增加后的身高为x，根据比例可得，x/h = 1.2。

解方程可得，x = 1.2h。

因此，袋鼠的身高增加了20%。

3. 利用图形方法解答：
设狗的身高为h，袋鼠的身高为1/4h。

袋鼠的体重为w，狗的体重为2w。

根据题意可得，袋鼠的体重增加20%，即原体重的1.2倍，即1.2w。

画出狗和袋鼠的身高和体重的比较图，可以观察到袋鼠的身高增加了20%后，狗和袋鼠的身高之间的比例关系仍然保持不变。

综上所述，袋鼠的身高增加了约84.3%。

美国袋鼠数学竞赛试题及答案

美国袋鼠数学竞赛试题及答案一、选择题（每题2分，共10分）1. 如果一个数的平方等于81，那么这个数是：A. 9B. -9C. 3D. -32. 下列哪个分数是最接近0.5的？A. 0.49B. 0.51C. 0.48D. 0.523. 如果一个圆的半径是5厘米，那么它的周长是多少厘米？A. 15πB. 10πC. 20πD. 25π4. 一个班级有30名学生，其中1/3是男生，其余是女生。

这个班级有多少名女生？A. 20B. 10C. 15D. 55. 一个数的立方是-27，这个数是：A. -3B. 3C. -27D. 27二、填空题（每题3分，共15分）6. 如果一个数的平方根是4，那么这个数是______。

7. 一个直角三角形的两条直角边分别是3和4，那么它的斜边长度是______。

8. 一个数的1/4加上5等于10，这个数是______。

9. 如果一个数的1/5是2，那么这个数是______。

10. 一个数的2倍加上3等于11，这个数是______。

三、解答题（每题5分，共20分）11. 一个长方形的长是20厘米，宽是10厘米，求它的面积。

12. 如果一个数的平方加上这个数等于10，求这个数。

13. 一个圆的直径是14厘米，求它的面积。

14. 一个数的立方加上这个数的平方再加上这个数等于64，求这个数。

答案1. B（-9的平方是81）2. B（0.51最接近0.5）3. C（周长=2πr，r=5，所以周长=2*π*5=10π）4. A（女生人数=30*(2/3)=20）5. A（-3的立方是-27）6. 16（4的平方是16）7. 5（根据勾股定理，斜边=√(3^2+4^2)=5）8. 36（设这个数为x，x/4+5=10，解得x=36）9. 10（设这个数为x，x/5=2，解得x=10）10. 4（设这个数为x，2x+3=11，解得x=4）11. 面积=长*宽=20*10=200平方厘米12. 设这个数为x，x^2+x=10，解得x=(-1+√41)/2 或 x=(-1-√41)/2（舍去负根）13. 面积=πr^2，r=直径/2=7，所以面积=π*7^2=49π平方厘米14. 设这个数为x，x^3+x^2+x=64，解得x=4结束语希望这份试题能够帮助同学们更好地准备美国袋鼠数学竞赛，同时也能够激发大家学习数学的热情。

2013 -美国袋鼠数学一二年级竞赛练习题

SAMPLE QUESTION FOR 3 POINTSWhich digits are missing on the right?A) 3 and 5 B) 4 and 8 C) 2 and 0 D) 6 and 9 E) 7 and 1SAMPLE QUESTION FOR 4 POINTSGeorge has 2 cats of the same weight. What is the weight of one cat if George weighs 30 kilograms?A) 1 kilogram B) 2 kilograms C) 3 kilogramsD) 4 kilograms E) 5 kilogramsSAMPLE QUESTION FOR 5 POINTSIn a certain game it is possible to make the following exchanges:Adam has 6 pears. How many strawberries will Adam have after he trades all his pears for just strawberries?A) 12 B) 36 C) 18 D) 24 E) 6SAMPLE QUESTION FOR 3 POINTSWhich digits are missing on the right?A) 3 and 5 B) 4 and 8 C) 2 and 0 D) 6 and 9E) 7 and 1SAMPLE QUESTION FOR 4 POINTSGeorge has 2 cats of the same weight. What is the weight of one cat if George weighs 30 kilograms?A) 1 kilogram B) 2 kilograms C) 3 kilogramsD) 4 kilograms E) 5 kilogramsSAMPLE QUESTION FOR 5 POINTSIn a certain game it is possible to make the following exchanges:Adam has 6 pears. How many strawberries will Adam have after he trades all his pears for just strawberries?A) 12 B) 36 C) 18D) 24 E) 6SAMPLE QUESTION FOR 3 POINTSIn which figure is the number of black kangaroos larger than the number of white kangaroos?SAMPLE QUESTION FOR 4 POINTSEach time Pinocchio lies, his nose gets 6 cm longer. Each time he tells the truth, his nose gets 2 cm shorter. After his nose was 9 cm long, he told three lies and made two true statements. How long was Pinocchio's nose afterwards?A) 14 cm B) 15 cm C) 19 cm D) 23 cm E) 31 cmSAMPLE QUESTION FOR 5 POINTSJoining the midpoints of the sides of the triangle in the drawing we obtain a smaller triangle. We repeat this one more time with the smaller triangle. How many triangles of the same size as the smallest resulting triangle fit in the original drawing?A) 5 B) 8 C) 10 D) 16 E) 32SAMPLE QUESTION FOR 3 POINTSIn which figure is the number of black kangaroos larger than the number of white kangaroos?SAMPLE QUESTION FOR 4 POINTSEach time Pinocchio lies, his nose gets 6 cm longer. Each time he tells the truth, his nose gets 2 cm shorter. After his nose was 9 cm long, he told three lies and made two true statements. How long was Pinocchio's nose afterwards?A) 14 cm B) 15 cm C) 19 cm D) 23 cm E) 31 cmSAMPLE QUESTION FOR 5 POINTSJoining the midpoints of the sides of the triangle in the drawing we obtain a smaller triangle. We repeat this one more time with the smaller triangle. How many triangles of the same size as the smallest resulting triangle fit in the original drawing?A) 5 B) 8 C) 10 D) 16E) 32SAMPLE QUESTION FOR 3 POINTSNathalie wanted to build the same cube as Diana had (Figure 1). However, Nathalie ran out of small cubes and built only a part of the cube, as you can see in Figure 2. How many small cubes must be added to Figure 2 to form Figure 1?A) 5 B) 6 C) 7 D) 8 E) 9SAMPLE QUESTION FOR 4 POINTSMary shades various shapes on square sheets of paper, as shown.How many of these shapes have the same perimeter as the sheet of paper itself?A) 2 B) 3 C) 4 D) 5 E) 6SAMPLE QUESTION FOR 5 POINTSThere are four buttons in a row as shown below. Two of them show happy faces, and two of them show sad faces. If we press on a face, its expression turns to the opposite (e.g. a happy face turns into a sad face). In addition to this, the adjacent buttons also change their expressions to the opposite. What is the least number of times you need to press the buttons in order to get all happy faces?A) 2 B) 3 C) 4 D) 5 E) 6SAMPLE QUESTION FOR 3 POINTSNathalie wanted to build the same cube as Diana had (Figure 1). However, Nathalie ran out of small cubes and built only a part of the cube, as you can see in Figure 2. How many small cubes must be added to Figure 2 to form Figure 1?A) 5 B) 6 C) 7D) 8 E) 9SAMPLE QUESTION FOR 4 POINTSMary shades various shapes on square sheets of paper, as shown.How many of these shapes have the same perimeter as the sheet of paper itself?A) 2 B) 3 C) 4D) 5 E) 6SAMPLE QUESTION FOR 5 POINTSThere are four buttons in a row as shown below. Two of them show happy faces, and two of them show sad faces. If we press on a face, its expression turns to the opposite (e.g. a happy face turns into a sad face). In addition to this, the adjacent buttons also change their expressions to the opposite. What is the least number of times you need to press the buttons in order to get all happy faces?A) 2 B) 3C) 4 D) 5 E) 6SAMPLE QUESTION FOR 3 POINTSIn the picture, the big triangle is equilateral and has an area of 9. The lines are parallel to the sides and divide the sides into three equal parts. What is the area of the shaded part?A) 1 B) 4 C) 5 D) 6 E) 7SAMPLE QUESTION FOR 4 POINTSVasya wrote down several consecutive integers. Which of the following could not be the percentage of odd numbers among them?A) 40 B) 45 C) 48 D) 50 E) 60SAMPLE QUESTION FOR 5 POINTSThe diagram shows a shaded quadrilateral KLMN drawn on a grid. Each cell of the grid has sides of length 2 cm. What is the area of KLMN?A) 96 cm2B) 84 cm2C) 76 cm2D) 88 cm2E) 104 cm2SAMPLE QUESTION FOR 3 POINTSIn the picture, the big triangle is equilateral and has an area of 9. The lines are parallel to the sides and divide the sides into three equal parts. What is the area of the shaded part?A) 1 B) 4 C) 5 D) 6E) 7SAMPLE QUESTION FOR 4 POINTSVasya wrote down several consecutive integers. Which of the following could not be the percentage of odd numbers among them?A) 40 B) 45C) 48 D) 50 E) 60SAMPLE QUESTION FOR 5 POINTSThe diagram shows a shaded quadrilateral KLMN drawn on a grid. Each cell of the grid has sides of length 2 cm. What is the area of KLMN?A) 96 cm2B) 84 cm2C) 76 cm2D) 88 cm2E) 104 cm2SAMPLE QUESTION FOR 3 POINTSThe number 200013 – 2013 is not divisible byA) 2. B) 3. C) 5. D) 7. E) 11.SAMPLE QUESTION FOR 4 POINTSThe points P and Q are opposite vertices of a regular hexagon and the points R and S are the midpoints of opposite edges, as shown. The area of the hexagon is 60 cm2. What is the product of the lengths of PQ and RS?A) 40 cm2B) 50 cm2C) 60 cm2D) 80 cm2E) 100 cm2SAMPLE QUESTION FOR 5 POINTSHow many positive integers are multiples of 2013 and have exactly 2013 divisors (including 1 and the number itself)?A) 0 B) 1 C) 3 D) 6 E) other answerSAMPLE QUESTION FOR 3 POINTSThe number 200013 – 2013 is not divisible byA) 2. B) 3. C) 5. D) 7.E) 11.SAMPLE QUESTION FOR 4 POINTSThe points P and Q are opposite vertices of a regular hexagon and the points R and S are the midpoints of opposite edges, as shown. The area of the hexagon is 60 cm2. What is the product of the lengths of PQ and RS?A) 40 cm2B) 50 cm2C) 60 cm2D) 80 cm2E) 100 cm2SAMPLE QUESTION FOR 5 POINTSHow many positive integers are multiples of 2013 and have exactly 2013 divisors (including 1 and the number itself)?A) 0 B) 1 C) 3 D) 6E) other answerLEVELS 11 AND 12SAMPLE QUESTION FOR 3 POINTSWhich of the following numbers is the largest?A) 2013 B) 20+13C) 2013 D) 2013E) 20 ·13SAMPLE QUESTION FOR 4 POINTSRadu has identical plastic pieces in the shape of a regular pentagon. He glues them edge to edge to complete a circle, as shown in the picture. How many pieces are there in this circle?A) 8 B) 9 C) 10 D) 12 E) 15SAMPLE QUESTION FOR 5 POINTSHow many pairs (x, y) of integers with x < y exist such that their product equals 5 times their sum?A) 4 B) 5 C) 6 D) 7 E) 8LEVELS 11 AND 12 ANSWERSSAMPLE QUESTION FOR 3 POINTSWhich of the following numbers is the largest?A) 2013 B) 20+13C) 2013 D) 2013E) 20 ·13SAMPLE QUESTION FOR 4 POINTSRadu has identical plastic pieces in the shape of a regular pentagon. He glues them edge to edge to complete a circle, as shown in the picture. How many pieces are there in this circle?A) 8 B) 9 C) 10D) 12 E) 15SAMPLE QUESTION FOR 5 POINTSHow many pairs (x, y) of integers with x < y exist such that their product equals 5 times their sum?A) 4B) 5 C) 6 D) 7 E) 8。

袋鼠数学数学竞赛试题

袋鼠数学数学竞赛试题袋鼠数学数学竞赛试题（详细版）第一部分：选择题（共10道题，每题4分，共40分）1. 若方程组 $2x+3y=7$，$5x-4y=8$ 的解为 $(a,b)$ ，求 $a+b$ 的值。

A. 1B. 2C. 3D. 42. 在一个等边三角形的内部有一个圆，圆与三角形的边相切，圆的半径为 4 cm。

求该等边三角形的边长。

A. 8 cmB. 12 cmC. 16 cmD. 24 cm3. 数列 $\{a_n\}$ 满足 $a_1=1$，$a_2=2$，$a_3=4$，$a_n=a_{n-1}+a_{n-2}+a_{n-3}$ （$n \geq 4$）。

则 $a_8$ 的值为多少？A. 29B. 32C. 33D. 364. 已知正方形 $ABCD$ 的边长为 8 cm，点 $P$ 在边 $AB$ 上，点$Q$ 在边 $CD$ 上，且 $AP=3$ cm，$CQ=4$ cm。

连接 $PQ$ ，求$PQ$ 的长度。

A. 3 cmB. 4 cmC. 5 cmD. 6 cm5. 在等差数列 $\{a_n\}$ 中，$a_1=3$，$a_5=11$。

求 $a_{10}$ 的值。

A. 19B. 20C. 21D. 226. 若 $a$ 的值满足 $a^3-7a^2+16a-12=0$，求 $a^2-3a+6$ 的值。

A. 8B. 10C. 12D. 147. 已知 $\triangle ABC$ 的三边分别为 $AB=8$ cm，$AC=6$ cm，$BC=10$ cm。

点 $D$ 在边 $BC$ 上，且 $BD=4$ cm。

若 $\angle DAB=60^\circ$，求 $\angle ACD$ 的度数。

A. $30^\circ$B. $45^\circ$C. $60^\circ$D. $75^\circ$8. 函数 $f(x)$ 为实数域上的线性函数，且满足 $f(3)=-4$，$f(5)=6$。

2021 -美国袋鼠数学一二年级竞赛练习题

SAMPLE QUESTION FOR 3 POINTS6. The pink tower is taller than the red tower but shorter than the green tower. The silver tower is taller than the green tower. Which tower is the tallest?(A) pink tower (B) green tower (C) red tower (D) silver tower(E) We don’t know.SAMPLE QUESTION FOR 4 POINTS15. The picture shows the five houses of five friends and their school. The school is the largest building in the picture. To go to school, Doris and Ali walk past Leo’s house. Eva walks past Chole’s house. Which is Eva’s house?(A) (B) (C) (D) (E) SAMPLE QUESTION FOR 5 POINTS18. Every time the witch has 3 apples, she turns them into 1 banana. Every time she has3 bananas, she turns them into 1 apple. What will she end up with if she starts with4 apples and5 bananas?(A) (B) (C) (D) (E)SAMPLE QUESTION FOR 3 POINTS6. The pink tower is taller than the red tower but shorter than the green tower. The silver tower is taller than the green tower. Which tower is the tallest?(A) pink tower (B) green tower (C) red tower (D) silver tower(E) We don’t know.SAMPLE QUESTION FOR 4 POINTS15. The picture shows the five houses of five friends and their school. The school is the largest building in the picture. To go to school, Doris and Ali walk past Leo’s house. Eva walks past Chole’s house. Which is Eva’s house?(A) (B)(C) (D) (E) SAMPLE QUESTION FOR 5 POINTS18. Every time the witch has 3 apples, she turns them into 1 banana. Every time she has3 bananas, she turns them into 1 apple. What will she end up with if she starts with4 apples and5 bananas?(A)(B) (C) (D) (E)SAMPLE QUESTION FOR 3 POINTS2. How many fish will have their heads pointing towards the ring when we straighten the line?(A) 3 (B) 5 (C) 6 (D) 7 (E) 8SAMPLE QUESTION FOR 4 POINTS15. On a tall building there are 4 fire escape ladders, as shown. The heightsof 3 ladders are at their tops. What is the height of the shortest ladder?(A) 12 (B) 14 (C) 16 (D) 20 (E) 22SAMPLE QUESTION FOR 5 POINTS23. Elena wants to write the numbers from 1 to 9 in the squares shown. The arrows always point from a smaller number to a larger one. She has already written 5 and 7. Which number should she write instead of the question mark?(A) 2 (B) 3 (C) 4 (D) 6 (E) 8SAMPLE QUESTION FOR 3 POINTS2. How many fish will have their heads pointing towards the ring when we straighten the line?(A) 3 (B) 5 (C) 6 (D) 7 (E) 8SAMPLE QUESTION FOR 4 POINTS15. On a tall building there are 4 fire escape ladders, as shown. The heightsof 3 ladders are at their tops. What is the height of the shortest ladder?(A) 12 (B) 14 (C) 16 (D) 20 (E) 22SAMPLE QUESTION FOR 5 POINTS23. Elena wants to write the numbers from 1 to 9 in the squares shown. The arrows always point from a smaller number to a larger one. She has already written 5 and 7. Which number should she write instead of the question mark?(A) 2 (B) 3 (C) 4 (D) 6 (E) 8SAMPLE QUESTION FOR 3 POINTS10. There is a square with line segments drawn inside it. The line segments are drawn either from the vertices or the midpoints of other line segments. We colored 18 of the large square. Which one is our coloring?(A) (B) (C) (D) (E)SAMPLE QUESTION FOR 4 POINTS13. Rosa wants to start at the arrow, follow the line, and get out at the other arrow. Which piece, if placed in the middle, cannot produce this? Note: The piece can be rotated.(A) (B) (C) (D) (E)SAMPLE QUESTION FOR 5 POINTS29. 10 elves and trolls each were given a token with a different number from 1 to 10 written on it. They were each asked what number was on their token and all answered with a number from 1 to 10. The sum of the answers was 36. Each troll told a lie and each elf told the truth. What is the smallest number of trolls there could be in the group?(A) 1 (B) 3 (C) 4 (D) 5 (E) 7SAMPLE QUESTION FOR 3 POINTS10. There is a square with line segments drawn inside it. The line segments are drawn either from the vertices or the midpoints of other line segments. We colored 18 of the large square. Which one is our coloring?(A) (B) (C) (D)(E)SAMPLE QUESTION FOR 4 POINTS13. Rosa wants to start at the arrow, follow the line, and get out at the other arrow. Which piece, if placed in the middle, cannot produce this? Note: The piece can be rotated.(A) (B) (C) (D) (E)SAMPLE QUESTION FOR 5 POINTS29. 10 elves and trolls each were given a token with a different number from 1 to 10 written on it. They were each asked what number was on their token and all answered with a number from 1 to 10. The sum of the answers was 36. Each troll told a lie and each elf told the truth. What is the smallest number of trolls there could be in the group?(A) 1 (B) 3 (C) 4 (D) 5 (E) 7SAMPLE QUESTION FOR 3 POINTS5. When the five pieces shown fit together correctly, the result is a rectangle with a calculationwritten on it. What is the result of this calculation?(A) –100 (B) –8 (C) –1 (D) 199 (E) 208SAMPLE QUESTION FOR 4 POINTS13. The area of the large square is 16 cm 2 and the area of each small square is 1 cm 2. What is the total area of the black flower?(A) 3 cm 2(B) 72 cm 2(C) 4 cm 2(D) 112 cm 2(E) 6 cm 2SAMPLE QUESTION FOR 5 POINTS26. 2021 colored kangaroos are arranged in a row and are numbered from 1 to 2021. Eachkangaroo is colored red, gray, or blue. Among any three consecutive kangaroos, there are always kangaroos of all three colors. Bruce guesses the colors of five kangaroos. These are his guesses: Kangaroo 2 is gray; Kangaroo 20 is blue; Kangaroo 202 is red; Kangaroo 1002 is blue; Kangaroo 2021 is gray. Only one of his guesses is wrong. What is the number of the kangaroo whose color he guessed incorrectly?(A) 2 (B) 20 (C) 202 (D) 1002 (E) 2021SAMPLE QUESTION FOR 3 POINTS5. When the five pieces shown fit together correctly, the result is a rectangle with a calculation written on it. What is the result of this calculation?(A) –100 (B) –8 (C) –1 (D) 199 (E) 208SAMPLE QUESTION FOR 4 POINTS13. The area of the large square is 16 cm2 and the area of each smallsquare is 1 cm2. What is the total area of the black flower?(A) 3 cm2(B) 72 cm2(C) 4 cm2(D) 112 cm2(E) 6 cm2SAMPLE QUESTION FOR 5 POINTS26. 2021 colored kangaroos are arranged in a row and are numbered from 1 to 2021. Each kangaroo is colored red, gray, or blue. Among any three consecutive kangaroos, there are always kangaroos of all three colors. Bruce guesses the colors of five kangaroos. These are his guesses: Kangaroo 2 is gray; Kangaroo 20 is blue; Kangaroo 202 is red; Kangaroo 1002 is blue; Kangaroo 2021 is gray. Only one of his guesses is wrong. What is the number of the kangaroo whose color he guessed incorrectly?(A) 2 (B) 20 (C) 202 (D) 1002 (E) 2021SAMPLE QUESTION FOR 3 POINTS1. Each year, the third Thursday in March is named Kangaroo Day. The dates of Kangaroo Day for the next few years are shown below, with one error. Which date is wrong?(A) March 17, 2022 (B) March 16, 2023 (C) March 14, 2024(D) March 20, 2025 (E) March 19, 2026SAMPLE QUESTION FOR 4 POINTS13. The numbers from 1 to 6 are placed in the circles at the intersections of three rings.The position of number 6 is shown. The sums of the numbers on each ring are the same. What number is placed in the circle with the question mark?(A) 1 (B) 2 (C) 3 (D) 4 (E) 5SAMPLE QUESTION FOR 5 POINTS25. The smaller square in the picture has an area of 16 and the gray triangle has an area of 1. What is the area of the larger square?(A) 17 (B) 18 (C) 19 (D) 20 (E) 21SAMPLE QUESTION FOR 3 POINTS1. Each year, the third Thursday in March is named Kangaroo Day. The dates of Kangaroo Day for the next few years are shown below, with one error. Which date is wrong?(A) March 17, 2022 (B) March 16, 2023 (C) March 14, 2024(D) March 20, 2025 (E) March 19, 2026SAMPLE QUESTION FOR 4 POINTS13. The numbers from 1 to 6 are placed in the circles at the intersections of three rings.The position of number 6 is shown. The sums of the numbers on each ring are the same. What number is placed in the circle with the question mark?(A) 1 (B) 2 (C) 3 (D) 4 (E) 5SAMPLE QUESTION FOR 5 POINTS25. The smaller square in the picture has an area of 16 and the gray triangle has an area of 1. What is the area of the larger square?(A) 17 (B) 18 (C) 19 (D) 20 (E) 21LEVELS 11 AND 12SAMPLE QUESTION FOR 3 POINTS1. Paula’s weather app shows a diagram of the predicted weather and maximum temperatures for the next seven days, as shown. Which of the following represents the corresponding graph of maximum temperatures?(A) (B) (C)(D) (E)SAMPLE QUESTION FOR 4 POINTS19. A naughty puppy grabs the end of a roll of toilet paper and walks away at a constant speed. Which of the functions below best describes the thickness y of the roll as a function of the unrolled part x?(A) (B) (C)(D) (E)SAMPLE QUESTION FOR 5 POINTS30. A certain game is won when one player gets 3 points ahead. Two players A and B are playingthe game and at a particular point, A is 1 point ahead. Each player has an equal probability of winning each point. What is the probability that A wins the game?(A) 12(B) 23(C) 34(D) 45(E) 56LEVELS 11 AND 12 ANSWERSSAMPLE QUESTION FOR 3 POINTS1. Paula’s weather app shows a diagram of the predicted weather and maximum temperatures for the next seven days, as shown. Which of the following represents the corresponding graph of maximum temperatures?(A) (B) (C)(D) (E)SAMPLE QUESTION FOR 4 POINTS19. A naughty puppy grabs the end of a roll of toilet paper and walks away at a constant speed. Which of the functions below best describes the thickness y of the roll as a function of the unrolled part x?(A) (B) (C)(D) (E)SAMPLE QUESTION FOR 5 POINTS30. A certain game is won when one player gets 3 points ahead. Two players A and B are playingthe game and at a particular point, A is 1 point ahead. Each player has an equal probability of winning each point. What is the probability that A wins the game?(A) 12(B)23(C) 34(D) 45(E) 56。

袋鼠数学数学竞赛中文试题

袋鼠数学数学竞赛中文试题袋鼠数学数学竞赛中文试题Ⅰ.选择题（每题2分，共10分）1. 下列哪个数是一个素数？A. 25B. 31C. 42D. 502. A、B、C三个人分别携带了2本、3本、5本书，他们总共带了多少本书？A. 6B. 10C. 9D. 73. 一些苹果在3个篮子中平均分配，每个篮子得到10个苹果，若再将这些苹果平均分配到6个篮子中，则每个篮子得到多少个苹果？A. 5B. 10C. 15D. 204. 甲、乙、丙三个人分别花费400元、600元、800元购买了一些物品，他们所花费的总金额是多少元？A. 800B. 1200C. 1800D. 16005. 若9+4x=25，则x的值是多少？A. 4B. 3C. 5D. 2Ⅱ.填空题（每题3分，共15分）1. 一个整数减去两个负整数之和能是正整数吗？为什么？________________________________________________2. 一个多边形的内角和是2160°，这个多边形有多少个角？________________________________________________3. 甲、乙两个容器分别装有2升和3升的水，如何只用这两个容器倒水，可以得到1升的水？________________________________________________4. 如果一个数的平方加上这个数的2倍等于18，求出这个数。

________________________________________________5. 某树在一年内的生长长度是150厘米，第一季度它的生长长度是前两个季度长度之和的1.5倍，第二季度它的生长长度是前两个季度长度之和的0.5倍，求出第三季度它的生长长度。

________________________________________________Ⅲ.解答题（每题10分，共30分）1. 中国的国旗是由什么颜色组成的？每种颜色的面积占比是多少？________________________________________________2. 一辆火车从A站出发，以每小时100千米的速度前进，过了1小时到达B站。

2007-美国袋鼠数学一二年级竞赛练习题

LEVELS 1 AND 2SAMPLE QUESTION FOR 3 POINTSWhich toy comes before the 5th toy?A) B) C) D) E)SAMPLE QUESTION FOR 4 POINTSWhich letter is missing from each of the words below? SCHOL BOK PRBLEM QUESTINA) A B) E C) O D) I E) USAMPLE QUESTION FOR 5 POINTSWhich number should replace the question mark in the pyramid?A) 10 B) 14 C) 22 D) 24 E) 34LEVELS 1 AND 2 ANSWERSSAMPLE QUESTION FOR 3 POINTSWhich toy comes before the 5th toy?A) B) C) D)E)SAMPLE QUESTION FOR 4 POINTSWhich letter is missing from each of the words below? SCHOL BOK PRBLEM QUESTINA) A B) E C) O D) I E) USAMPLE QUESTION FOR 5 POINTSWhich number should replace the question mark in the pyramid?A) 10 B) 14 C) 22 D) 24E) 34LEVELS 3 AND 4SAMPLE QUESTION FOR 3 POINTSNot taking any steps backwards, Anna travelled toward the car using a path shown in the picture, and picked up numbers she encountered along her way. Which set of the numbers below could she pick up?A) 1, 2, 4 B) 2, 3, 4 C) 2, 3, 5 D) 1, 5, 6 E) 1, 2, 5SAMPLE QUESTION FOR 4 POINTSThe square shown in the picture must be filled in such a way that each of thedigits 1, 2, and 3 appears in each row and in each column once and onlyonce. If Harry started to fill in the square as shown, what number can hewrite in the square marked with the question mark?A) 1 B) 2 C) 3 D) 1 or 2 E) 1, 2 or 3SAMPLE QUESTION FOR 5 POINTSHow many digits have to be written in order to write down every number from 1 to 100 inclusive?A) 100 B) 150 C) 190 D) 192 E) 200LEVELS 3 AND 4 ANSWERSSAMPLE QUESTION FOR 3 POINTSNot taking any steps backwards, Anna travelled toward the car using a path shown in the picture, and picked up numbers she encountered along her way. Which set of the numbers below could she pick up?A) 1, 2, 4 B) 2, 3, 4 C) 2, 3, 5D) 1, 5, 6 E) 1, 2, 5SAMPLE QUESTION FOR 4 POINTSThe square shown in the picture must be filled in such a way that each of thedigits 1, 2, and 3 appears in each row and in each column once and onlyonce. If Harry started to fill in the square as shown, what number can hewrite in the square marked with the question mark?A) 1 B) 2 C) 3D) 1 or 2 E) 1, 2 or 3SAMPLE QUESTION FOR 5 POINTSHow many digits have to be written in order to write down every number from 1 to 100 inclusive?A) 100 B) 150 C) 190 D) 192E) 200LEVELS 5 AND 6SAMPLE QUESTION FOR 3 POINTSEvaluate 2007 ÷ (2 + 0 + 0 + 7) – 2 × 0 × 0 × 7A) 1 B) 9 C) 214 D) 223 E) 2007SAMPLE QUESTION FOR 4 POINTSAlex, Ben, Carl, and Daniel each participates in a different sport: karate, soccer, volleyball, and judo. Alex does not like sports played with a ball. Ben practices judo and often attends soccer games to watch his friend play. Which of the following statements is true?A) Alex plays volleyball.B) Ben plays soccer.C) Carl plays volleyball.D) Daniel does karate.E) Alex does judo.SAMPLE QUESTION FOR 5 POINTSTo the right of a certain two-digit number the same number has been written, creating a four-digit number. How many times is the new four-digit number greater than the original two-digit number?A) 100 B) 101 C) 1000 D) 1001 E) 10LEVELS 5 AND 6 ANSWERSSAMPLE QUESTION FOR 3 POINTSEvaluate 2007 ÷ (2 + 0 + 0 + 7) – 2 × 0 × 0 × 7A) 1 B) 9 C) 214 D) 223E) 2007SAMPLE QUESTION FOR 4 POINTSAlex, Ben, Carl, and Daniel each participates in a different sport: karate, soccer, volleyball, and judo. Alex does not like sports played with a ball. Ben practices judo and often attends soccer games to watch his friend play. Which of the following statements is true?A) Alex plays volleyball.B) Ben plays soccer.C) Carl plays volleyball.D) Daniel does karate.E) Alex does judo.SAMPLE QUESTION FOR 5 POINTSTo the right of a certain two-digit number the same number has been written, creating a four-digit number. How many times is the new four-digit number greater than the original two-digit number?A) 100 B) 101C) 1000 D) 1001 E) 10LEVELS 7 AND 8SAMPLE QUESTION FOR 3 POINTSRose bushes are planted in a line on both sides of a path. The distance between the bushes is 2 m. What is the largest number of bushes that can be planted if the path is 20 m long?A) 22 B) 20 C) 12 D) 11 E) 10SAMPLE QUESTION FOR 4 POINTSx is a strictly negative integer. Which of the expressions is the greatest?A) x + 1 B) 2x C) −2x D) 6x + 2 E) x − 2SAMPLE QUESTION FOR 5 POINTSA certain broken calculator does not display the digit 1. For example, if we type in the number 3131, only the number 33 is displayed, with no spaces. Mike typed a 6-digit number into that calculator, but only 2007 appeared on the display. How many different numbers could Mike have typed?A) 12 B) 13 C) 14 D) 15 E) 16LEVELS 7 AND 8 ANSWERSSAMPLE QUESTION FOR 3 POINTSRose bushes are planted in a line on both sides of a path. The distance between the bushes is 2 m. What is the largest number of bushes that can be planted if the path is 20 m long?A) 22B) 20 C) 12 D) 11 E) 10SAMPLE QUESTION FOR 4 POINTSx is a strictly negative integer. Which of the expressions is the greatest?A) x + 1 B) 2x C) −2x D) 6x + 2 E) x − 2SAMPLE QUESTION FOR 5 POINTSA certain broken calculator does not display the digit 1. For example, if we type in the number 3131, only the number 33 is displayed, with no spaces. Mike typed a 6-digit number into that calculator, but only 2007 appeared on the display. How many different numbers could Mike have typed?A) 12 B) 13 C) 14 D) 15E) 16LEVELS 9 AND 10SAMPLE QUESTION FOR 3 POINTSIn the picture, what is the sum of the number of dots on the faces of the dice which you cannot see?A) 15 B) 12 C) 7 D) 27 E) another answerSAMPLE QUESTION FOR 4 POINTSTo fill in the table, we need to write 0 or 1 in each cell in such a way that the sum of numbers of each row and of each column is equal to 2. What are x and y ? A) x = 1, y = 1 B) x = 1, y = 0 C) x = 0, y = 1D) x = 0, y = 0 E) It is impossible to determine.SAMPLE QUESTION FOR 5 POINTSA certain island is inhabited by liars and truth-tellers (the liars always lie and the truth-tellers always tell the truth). One day 12 islanders, both liars and truth-tellers, gathered together and issued a few statements. Two people said: “Exactly two people among us twelve are liars.” Four other people said: “Exactly four people among us twelve are liars.” The other six people said: “Exactly six people among us twelve are liars.” How many liars were there? A) 2 B) 4 C) 6 D) 8 E) 10LEVELS 9 AND 10 ANSWERSSAMPLE QUESTION FOR 3 POINTSIn the picture, what is the sum of the number of dots on the faces of the dice which you cannot see?A) 15 B) 12C) 7D) 27E) another answerSAMPLE QUESTION FOR 4 POINTSTo fill in the table, we need to write 0 or 1 in each cell in such a way that the sum of numbers of each row and of each column is equal to 2. What are x and y ? A) x = 1, y = 1 B) x = 1, y = 0C) x = 0, y = 1D) x = 0, y = 0 E) It is impossible to determine.SAMPLE QUESTION FOR 5 POINTSA certain island is inhabited by liars and truth-tellers (the liars always lie and the truth-tellers always tell the truth). One day 12 islanders, both liars and truth-tellers, gathered together and issued a few statements. Two people said: “Exactly two people among us twelve are liars.” Four other people said: “Exactly four people among us twelve are liars.” The other six people said: “Exactly six people among us twelve are liars.” How many liars were there? A) 2 B) 4C) 6D) 8E) 10LEVELS 11 AND 12SAMPLE QUESTION FOR 3 POINTSA billiard ball always bounces off the side of a billiard table at an angle of 45° as shown. If it continues on the path shown, which pocket will the ball fall into?A) A B) B C) C D) DE) The ball will not fall into any pocket.SAMPLE QUESTION FOR 4 POINTSThe square ABCD lies in a plane and its edge measures 1. Consider all squares that share at least two vertices with the square ABCD. What is the area of the region covered by all of such squares, not including ABCD?A) 5 B) 6 C) 7 D) 8 E) 9SAMPLE QUESTION FOR 5 POINTSWhat is the measure of the acute angle of a rhombus with side of length equal to the geometric mean of its diagonals?A) 15° B) 30° C) 45° D) 60° E) 75°LEVELS 11 AND 12 ANSWERSSAMPLE QUESTION FOR 3 POINTSA billiard ball always bounces off the side of a billiard table at an angle of 45° as shown. If it continues on the path shown, which pocket will the ball fall into?A) A B) B C) C D) DE) The ball will not fall into any pocket.SAMPLE QUESTION FOR 4 POINTSThe square ABCD lies in a plane and its edge measures 1. Consider all squares that share at least two vertices with the square ABCD. What is the area of the region covered by all of such squares, not including ABCD?A) 5 B) 6 C) 7D) 8 E) 9SAMPLE QUESTION FOR 5 POINTSWhat is the measure of the acute angle of a rhombus with side of length equal to the geometric mean of its diagonals?A) 15° B) 30°C) 45° D) 60° E) 75°。

2024袋鼠数学试卷

2024袋鼠数学试卷一、选择题（每题3分，共30分）1. 小明有10颗糖，给了小红3颗，又给了小刚2颗，小明还剩下几颗糖？（）A. 5颗B. 4颗C. 6颗D. 7颗。

2. 一个三角形的内角和是（）（人教版数学知识）A. 180°B. 360°C. 90°D. 270°.3. 计算：25×4÷2= （）A. 50B. 40C. 60D. 80.4. 在1 - 100这些自然数中，能被5整除的数有多少个？（）A. 19个B. 20个C. 21个D. 18个。

5. 一个正方形的边长为5厘米，它的面积是（）平方厘米。

A. 10B. 15C. 20D. 25.6. 观察下面的数列：1，3，5，7，9，……，这个数列的第10项是（）A. 19B. 21C. 17D. 23.7. 把(3)/(4)化成小数是（）A. 0.7B. 0.75C. 0.8D. 0.6.8. 直角三角形的两条直角边分别为3厘米和4厘米，它的斜边长为（）厘米。

（根据勾股定理，人教版知识）A. 5B. 6C. 7D. 8.9. 一桶油重10千克，用去了(3)/(5)，用去了多少千克？（）A. 6千克B. 4千克C. 8千克D. 5千克。

10. 一个圆柱的底面半径是2厘米，高是5厘米，它的侧面积是（）平方厘米。

（π取3.14）A. 62.8B. 31.4C. 125.6D. 94.2.二、填空题（每题4分，共20分）1. 3.14 +2.71 = _______。

2. 最小的质数是_______。

3. 一个数除以8，商是12，余数是5，这个数是_______。

4. 1小时20分钟 = _______分钟。

5. 从一副扑克牌（54张）中任意抽出一张，抽到黑桃的概率是_______（结果用最简分数表示）。

三、解答题（每题10分，共50分）1. 学校图书馆有故事书300本，科技书的数量是故事书的(2)/(3)，漫画书的数量是科技书的(3)/(4)，漫画书有多少本？2. 一个长方形的长是12厘米，宽是8厘米，求这个长方形的周长和面积。

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Kangourou Sans Fronti`e resMathematics Promotion Society Math Kangaroo in USAMath Kangaroo2012in USAInternational Competition in MathematicsThursday,March15,2012Levels1and2This test consists of24questions on4pages.You have75minutes to complete it.Calculators are not allowed!Please enter your answers on the answer form provided.Please put your name and ID number on the line below.3Point Problems1.How many animals are there in the picture to the right?A)3B)4C)5D)6E)72.Which pieceﬁts in the empty place in the puzzle on the right?A)B)C)D)3.How many legs do these animals have altogether?A)5B)10C)12D)14E)204.Helena wrote the word KANGAROO twice.How many times did she write the letter A?A)1B)2C)3D)4E)65.Luke repeats the same four stickers on astrip. Which is the tenth sticker put down by Luke?A)B)C)D)E)6.On Friday Dan starts to paint the word BANANA.Each day he paints one letter.On what day will he paint the last letter?A)Monday B)Tuesday C)Wednesday D)Thursday E)Friday7.Which of the bolded paths is the longest?A)A B)B C)C D)D E)E8.Katja is in a boat on a lake.Which of the pictures does she see in thelake?A)B)C)D)E) 4Point Problems9.13children are playing hide and seek.One of them is the“seeker.”After a while9children have been found.How many children are still hiding?A)3B)4C)5D)9E)2210.Father hangs the laundry outside on a clothesline.He wants to use as few pins as possible.For3towels he needs 4pins,as shown.How many pins does he need for9towels?A)9B)10C)12D)16E)1811.Today Betty added her age and her sister’s age and obtained10as the sum.What will the sum of their ages be one year from today?A)5B)10C)11D)12E)2012.The clock shows the time when Stephen leaves school.Lunch at school starts3hours before school ends.At what time does lunch start?A)1B)2C)5D)11E)1213.A dragon has3heads.Every time a hero cuts oﬀ1head,3new heads grow.The hero cuts1 head oﬀand then he cuts1head oﬀagain.How many heads does the dragon have now?A)4B)5C)6D)7E)814.Stars,clovers,gifts and trees repeat regularly on a game board. Some juice was spilled on the board.As a result some of the pictures can’t be seen(these are the white spaces in the picture).How many stars were on the board before the juice was spilled?A)3B)6C)8D)9E)2015.Eve brings12pieces of candy,Alice brings9pieces of candy and Irene doesn’t bring any candy. They put all the pieces of candy together on a table and divide them equally among themselves. How many pieces of candy does each of the girls get?A)3B)7C)8D)9E)1216.Tim is looking at seven silk paintings on a wall.On the left he sees the dragon and on the right thebutterﬂy.Which animal is to the left of the tiger and the lion,and to the right of the apricot?A)B)C)D)E) 5Point Problems17.Winnie the Pooh bought4apple pies and Eeyore bought6cheesecakes.They each paid the same amount of money and together they paid24euros.How many euros does1cheesecake cost?A)2B)4C)6D)10E)1218.Sparrow Jack jumps on a fence from one post to another.Each jump takes him1second.He makes 4jumps ahead,then1jump back and again4jumps ahead and1back,and so on.In how many seconds does Jack get from START toFINISH?A)10B)11C)12D)13E)1419.Grandmother made11cookies.She decorated5cookies with raisins and then7cookies with nuts.At least how many cookies were decorated with both raisins and nuts?A)1B)2C)5D)7E)1220.At a school party Dan,Jack and Ben each received a bag with10pieces of candy.Each of the boys ate just1piece of candy and gave1piece of candy to the teacher.How many pieces of candy do they have left altogether?A)8B)10C)24D)27E)3021.What number is covered by theﬂower?A)1B)2C)3D)4E)5=32435=422.Ann has a lot of these tiles:How many of the following shapes can Ann makeby gluing together two of thesetiles?A)0B)1C)2D)3E)423.In a box there are three boxes,and each one of these boxes contains three smaller boxes.How many boxes are there in total?A)9B)10C)12D)13E)1524.There are coins on the board.We want to have2coins in each column and2coins in each row.How many coins need to be removed?A)0B)1C)2D)3E)4Kangourou Sans Fronti`e res Math Kangaroo in USA Math Kangaroo2014in USAInternational Competition in MathematicsThursday,March20,2014Levels1and2This test consists of24questions on4pages.You have75minutes to complete it.Calculators are not allowed!Please enter your answers on the answer form provided.Please put your name and ID number on the line below.Problems3points each#1.The ladybug will sit on aﬂower that hasﬁve petals and three leaves.On which of theﬂowers below will the ladybug sit?(A)(B)(C)(D)(E)#2.If you start at the arrow and move along the line,in what order do youmeet the shapes?(A) , ,•(B) ,•, (C)•, , (D) , ,•(E) ,•,#3.How many more small gray squares are there than(A)6(B)7(C)8(D)9(E)10#4.Put the animals in order from the smallest to the largest.Give the number of the animal in the middle.(A)1(B)2(C)3(D)4(E)5#5.Ann has twelve of these tiles.She makes a design that is onecontinuous line.Ann starts at the left side of the grid,as shown in the picture.How does the line end on the right side of the grid?(A)(B)(C)(D)(E)#6.Which of the pictures below is the shadow of the girl?(A)(B)(C)(D)(E)#7.A square was made out of25small squares,but some of these small squares are nowmissing.How many small squares are missing?(A)6(B)7(C)8(D)10(E)12#8.How many ducks balance the crocodile?(A)(B)(C)(D)(E)Problems4points each#9.When the ant goes from home following thesearrows:→3,↑3,→3,↑1on the board to the right,it comes tothe ladybug.Which animal will it come to if it goes fromhome following these arrows:→2,↓2,→3,↑3,→2,↑2?(A)(B)(C)(D)(E)#10.The kangaroo is inside how many circles?(A)1(B)2(C)3(D)4(E)5Math Kangaroo 2014March 20,2014Levels 1and 2#11.A square was cut into 4parts as shown in the picture to the right.Whichof the following shapes cannot be made using only these 4parts?(A)(B )(C)(D )(E)#12.Which of the shapes shown below will ﬁt this shape exactly to make a rectangle?(A)(B)(C)(D)(E)#13.Walking from K to O along the lines,pick up the lettersKANGAROO in the correct order.What is the length of the shortestwalk in meters (1m =1meter)?(A )16m (B )17m (C )18m (D )19m (E )20m #14.How many numbers that are greater than 10and less than or equalto 31can be written with only the digits 1,2and 3?You can repeat digits.(A )2(B )4(C )6(D )7(E )8#15.Seven sticks lie on top of each other.Stick 2is atthe bottom.Stick 6is at the top.Which stick is in themiddle?(A )1(B )3(C )4(D )5(E )7#16.How many frogs did the three pelicans catchaltogether?(A )1(B )2(C )4(D )9(E )12Problems 5points each#17.The chess board is damaged.How many black squares are missingon the right side of the line?(A )11(B )12(C )13(D )14(E )15#19.What shouldyou put in the square on the bottomto get a correctdiagram?(A)−38(B )÷8(C )−45(D )×6(E )÷6#20.Put the digits 2,3,4and 5in the squares and calculate the sum to get the largest possible value.What is that value?(A )68(B )77(C )86(D )95(E )97#21.The central cell of the square was removed.We cut the rest of the squareinto identical pieces.Which type of piece is it not possible to get?(A )(B )(C )(D )(E )#22.To get the product of 2×3×15,Bill has to press the keys of his calculator seven times:.Bill wants to multiply all the numbers from 3to 21using his calcu-lator.At least how many times will he press the keys of his calculator?(A )19(B )31(C )37(D )50(E )60#23.Fred has 4red cubes,3blue cubes,2green cubes and 1yellow cube.Hebuilds a tower (see the picture)in such a way that no two adjacent cubes have thesame color.What color is the cube with the question mark?(A )red (B )blue (C )green (D )yellow(E )It is impossible to determine.#24.Cogwheel A turns around completely once.At which place is x now?x C A (A )a (B )b (C )c (D )d (E )eKangourou Sans Fronti`e res Math Kangaroo in USA Math Kangaroo2015in USAInternational Competition in MathematicsThursday,March19,2015This test consists of24questions on4pages.You have75minutes to complete it.Calculators are not allowed!Please enter your answers on the answer form provided.Please put your name and ID number on the line below.Levels1and23points#1.Look closely at these four pictures.Whichﬁgure is missing from one of the pictures?(A)(B)(C)(D)(E)#2.Find the piece missing from the house on the right.(A)(B)(C)(D)(E)#3.There areﬁve ladybugs shown to the left.How many spots are there onall the ladybugs together?(A)17(B)18(C)19(D)20(E)21Math Kangaroo 2015March 19,2015Levels 1and 2#4.Which of the following pictures can be rotated so that it will be the same as the picture shown on the right?(A)(B)(C)(D)(E)#5.What does the tower shown to the right look like from above?(A)(B)(C)(D)(E)943728#6.The diagram to the left shows six numbers.What is the sum of thenumbers outside the square?(A )12(B )11(C )23(D )33(E )10#7.Half of a movie lasts half an hour.How long does the whole movie last?(A )15minutes(B )half an hour (C )1hour(D )2hours (E )40minutes #together into ﬁve long strips.Which connected strip is the shortest?(A )A(B )B (C )C (D )D (E )E4points#9.There are 11ﬂags on a straight race track.The ﬁrst ﬂag is at the start,and the last ﬂag is at the ﬁnish.The distance between each ﬂag is 4meters.How long is the track?(A )12meters (B )24meters (C )36meters (D )40meters (E )44meters #10.Marko has 9pieces of candy and Tomo has 17pieces of candy.How many pieces of candy does Tomo need to give to Marko so that each boy has the same number of pieces of candy?(A )2(B )3(C )4(D )5(E )6#12.When written as5/5/2015,the date Mayﬁfth,2015,has three5’s.The next earliest date that will have three5’s is:(A)May tenth,2015(B)Apriltwenty-ﬁfth,2015(C)May twenty-ﬁfth,2015(D)Januaryﬁfth,2055(E)Mayﬁfteenth,2015#13.Emil placed the numbers1,2,3,4,and5correctly inthe boxes in the diagram on the right.What number did heplace in the box with the question mark?(A)1(B)2(C)3(D)4(E)5#14.Vera invited13guests to her birthday party.She had2pizzas,and each of them was cut into8 slices.Each person at the party ate one slice of pizza.How many slices of pizza were left over?(A)5(B)4(C)3(D)2(E)1#15.Don has two identical bricks(see picture to the right).Whichﬁgure can he notbuild using these two bricks?(A)(B)(C)(D)(E)#16.Which piece is missing from the puzzle to the right?(A)(B)(C)(D)(E)5points#17.In one jump,Jake the Kangaroo jumps from one circle to a neighboringcircle along a line,as shown in the picture to the right.He cannot jump intoany circle more than once.He starts at circle S and needs to make exactly4jumps to get to circle F.In how many diﬀerent ways can Jake do this?(A)3(B)4(C)5(D)6(E)7S F#18.A ship was attacked by pirates.One by one,the pirates climbed a rope to get to the ship.The pirate captain was the eighth pirate to climb,and there were as many pirates in front of him as behind him.How many pirates climbed the rope?(A)7(B)8(C)12(D)15(E)16Math Kangaroo2015March19,2015Levels1and2 #19.For3days,Joy the cat was catching mice.Each day Joy caught2mice more than the previous day.On the third day Joy caught twice as many mice as on theﬁrst day.In total,how many mice did Joy catch during the three days?(A)12(B)15(C)18(D)20(E)24#20.The numbers3,5,7,8and9were written in the squares of the cross(see theﬁgure to the right)so that the sum of the numbers in the row is equal to the sum ofthe numbers in the column.Which number was written in the central square?(A)3(B)5(C)7(D)8(E)9#21.My grandmother has a dog named Atos,as well as some ducks,hens and geese.She has40animals altogether.She has four times as many geese as ducks.Atos and the hens make up one half of all her animals.My grandmother has:(A)19hens and5ducks(B)20hens and4ducks(C)19hens and15geese(D)19hens and16geese(E)20hens and16geese#22.One of the six stickers shown below was placed on each of the six faces of a die.The next picture shows the die in two positions.Which picture is on the face opposite the face with the kangaroo sticker?(A)(B)(C)(D)(E)#23.Sylvia,Tara,Una and Wanda went out for dessert.They stood in line one after another.Each one of them ordered one of the following desserts:ice cream,waﬄe,bun,and cake,and each one ordered a diﬀerent item.We know that:•Theﬁrst girl did not buy the ice cream or the waﬄe.•Una was not last in line,and she bought the cake.•Sylvia,who was standing behind Tara and in front of Una,did not buy the waﬄe.Which of the following is true?(A)Wanda wasﬁrst in line.(B)Tara bought the ice cream.(C)Wanda bought the waﬄe. (D)Una was second in line.(E)Sylvia bought the bun.#24.We left for a summer camp yesterday at4:32PM and got to our destination today at6:11AM. How long did we travel?(A)13hours39minutes(B)14hours39minutes(C)14hours21minutes(D)13hours21minutes(E)2hours21minutes。