SAT学真题精选

SAT数学真题精选

1. If 2 x + 3 = 9, what is the value of 4 x – 3 ?

(A) 5 (B) 9 (C) 15 (D) 18 (E) 21

2. If 4(t + u) + 3 = 19, then t + u = ?

(A) 3 (B) 4 (C) 5 (D) 6 (E) 7

3. In the xy-coordinate (坐标) plane above, the line contains the points (0,0) and (1,2). If line M (not shown) contains the point (0,0) and is perpendicular （垂直）to L, what is an equation of M?

(A) y = -1/2 x (B) y = -1/2 x + 1 (C) y = - x (D) y = - x + 2 (E) y = -2x

4. If K is divisible by 2,3, and 15, which of the following is also divisible by these numbers?

(A) K + 5 (B) K + 15 (C) K + 20 (D) K + 30 (E) K + 45

5. There are 8 sections of seats in an auditorium. Each section contains at least 150 seats but not more than 200 seats. Which of the following could be the number of seats in this auditorium?

(A) 800 (B) 1,000 (C) 1,100 (D) 1,300 (E) 1,700

6. If rsuv = 1 and rsum = 0, which of the following must be true?

(A) r < 1 (B) s < 1 (C) u= 2 (D) r = 0 (E) m = 0

7. The least integer of a set of consecutive integers (连续整数) is –126. if the sum of these integers is 127, how many integers are in this set?

(A) 126 (B) 127 (C) 252 (D) 253 (E) 254

8. A special lottery is to be held to select the student who will live in the only deluxe room in a

dormitory. There are 200 seniors, 300 juniors, a nd 400 sophomores who applied. Each senior’s name is placed in the lottery 3 times; each junior’s name, 2 time; and each sophomore’s name, 1

times. If a student’s name is chosen at random from the names in the lottery, what is the probability that a senior’s name will be chosen?

（A）1/8 (B) 2/9 (C) 2/7 (D) 3/8 (E) 1/2

SAT考试数学练习题（一）

1. If f(x) = x²– 3, where x is an integer, which of the following could be a value of f(x)?

I 6

II 0

III -6

A. I only

B. I and II only

C. II and III only

D. I and III only

E. I, II and III

Correct Answer: A

解析:

Choice I is correct because f(x) = 6 when x=3. Choice II is incorrect because to make f(x) = 0, x²would have to be 3. But 3 is not the square of an integer. Choice III is incorrect because to make f(x) = 0, x² would have to be –3 but squares cannot be negative. (The minimum value for x2 is zero; hence, the minimum value for f(x) = -3)

2. For how many integer values of n will the value of the expression 4n + 7 be an integer greater than

1 and less than 200?

A. 48

B. 49

C. 50

D. 51

E. 52

Correct Answer: C

解析:

1 < 4n + 7 < 200. n can be 0, or -1. n cannot be -

2 or any other negative integer or the expression 4n + 7 will be less than1. The largest value for n will be an integer < (200 - 7) /4. 193/4 = 48.25, hence 48. The number of integers between -1 and 48 inclusive is 50

3. In the following correctly worked addition sum, A,B,C and D represent different digits, and all the digits in the sum are different. What is the sum of A,B,C and D?