SAT考试数学练习题 6
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.
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
B. 200
C. 440
D. 668
E. 762
Correct Answer: E
解析:
All terms in the sequence will be multiples of 4. 762 is not a multiple of 4