SAT数学练习题 含详细答案解析(2).

　　下面是5道SAT数学练习题，每道题目后面都有答案和详细的解析，希望同学们在练习的时候先不看答案，看看自己的能做对几道题，然后再与答案对照，找出错题原因，针对自己的SAT数学复习进行查漏补缺。

　　1. The distance from town A to town B is five miles. C is six miles from B. Which of the following could be the distance from A to C?

　　I 11

　　II 1

　　III 7

　　A. I only

　　B. II only

　　C. I and II only

　　D. II and III only

　　E. I, II, or III.

　　Correct Answer: E

　　解析:

　　Do not assume that AB and C are on a straight line. Make a diagram with A and B marked 5 miles apart. Draw a circle centered on B, with radius 6. C could be anywhere on this circle. The minimum distance will be 1, and maximum 11, but anywhere in between is possible.

　　2. √5 percent of 5√5 =

　　A. 0.05

　　B. 0.25

　　C. 0.5

　　D. 2.5

　　E. 25

　　Correct Answer: B

　　解析:

　　We can write the statement mathematically, using x to mean ‘of’ and /100 for ‘per cent’. So ( √5/100) x 5√5 = 5 x 5 /100 = 0.25

　　3. If pqr = 1 , rst = 0 , and spr = 0, which of the following must be zero?

　　A. P

　　B. Q

　　C. R

　　D. S

　　E. T

　　Correct Answer: D

　　解析:

　　If pqr = 1, none of these variable can be zero. Since spr = 0 , and since p and r are not zero, s must be zero. (Note that although rst = 0, and so either s or t must be zero, this is not sufficient to state which must be zero)

　　4.