五道SAT数学练习题及解析-西泽读留学

　　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:

　　4.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)

　　A. 1/5

　　B. 6/5

　　C. 63

　　D. 64 / 5

　　E. 64

　　Correct Answer: E

　　解析:

　　65 = 64x 6

　　(64 x 6) - 64 = 64(6 - 1) = 64 x 5 Now, dividing by 5 will give us 64

　　5. -20 , -16 , -12 , -8 ....

　　In the sequence above, each term after the first is 4 greater than the preceding term. Which of the following could not be a term in the sequence?

　　A. 0