How many integers from 1 to 900 inclusive have exactly 3 positive divisors? A. 10 B. 14 C. 15 D. 29 E. 30

答案：A

题目2

Let S be the set of all positive integers n such that n2 is a multiple of both 24 and 108. Which of the following integers are divisors of every integer n in S? Indicate all such integers. A. 12 B. 24 C. 36 D.72

答案：AC

题目3

What is the sum of all possible solutions to the equation: = + 1 A. -2 B. 2 C. 3 D. 5 E. 6

答案：D

题目4

If x is 4 more than half of y and if y is 10 more than half of x, what is the value of x? 答案：12

题目5

In the rectangular coordinate system, the point （3,1） is on the circle with center （0, -3）。 What is the area of the circle? A. 5π B. 7π C. 10π D. 25π E. π√7 答案：D

题目6

Which of the following statements about triangle PQR shown in the xy-plane are true? Indicate all such statements. A. PQR is a right triangle. B. The area of PQR is 15/2. C. PQR is an isosceles triangle 答案：C

题目7

In the xy-plane, triangular region R is bounded by the lines x = 0, y = 0, and 4x + 3y = 60. Which of the following points lie inside region R? Indicate all such points. A. （2, 18） B. （5, 12） C. （10, 7） D. （12, 3） E. （15, 2） 答案：BD

题目 8

For a sample of 210 households, one-third of the households do not have any pets, one-third of the households each have 1 pet, and the rest of the households each have 2 pets. Which of the following statistics for the sample are equal to 1? Indicate all such statistics. A. The average （arithmetic mean） number of pets per household. B. The median number of pets per household. C. The range of the numbers of pets per household. 答案：AB

题目9

The figure above shows the standard normal distribution, with mean 0 and standard deviation 1, including approximate percent of the distribution corresponding to the six regions shown. The random variable Y is normally distributed with a mean of 470, and the value Y = 340 is at the 15th percentile of the distribution. Of the following, which is the best estimate of the standard deviation of the distribution? A. 125 B. 135 C. 145 D. 155 E. 165 答案：A

题目10

The range of the heights of the female students in a certain class is 13.2 inches, and the range of the heights of the male students in the class is 15.4 inches. Which of the following statements individually provide（s） sufficient additional information to determine the range of the heights of all the students in the class? Indicate all such statements. A. The tallest male student in the class is 5.8 inches taller than the tallest female student in the class. B. The median height of the male students in the class is 1.1 inches greater than the median height of the female students in the class. C. The average （arithmetic mean） height of the male students in the class is 4.6 inches greater than the average height of the female students in the class. 答案：A

题目 11

In how many different ways can 3 identical green shirts and 3 identical red shirts be distributed among 6 children such that each child receives a shirt? A. 20 B. 40 C. 216 D. 720 E. 729 答案：A

题目12

In the figure above, AB=CD, ∠A=70°， ∠C=50°， the radius of the circle is 3. Then what is the length of minor arc AB? 答案：π