{{U}}Directions:{{/U}} In the following questions, choose the best answer from the five choices listed.

单选题 If 80% of the adult population of a village is registered to vote, and 60% of those registered actually voted in a particular election, what percent of the adults in the village did NOT vote in that election?

A、 (A) 20
B、 (B) 40
C、 (C) 48
D、 (D) 50
E、 (E) 52

【正确答案】 E

【答案解析】If there are x adults in the village, then .8x of them are registered and .6(8x) = .48x voted. Therefore, x -.48x = .52x or 52% of the adults did not vote. **You can avoid the algebra by assuming there are 100 adults. Then 80 of them are registered and 60% of 80 = 48 of them voted. So 52 did not vote, and

单选题 If

of a number is 7 more than

of the number, what is

of the number?

A、 (A) 12
B、 (B)15
C、 (C) 18
D、 (D) 20
E、 (E) 24

【正确答案】 D

【答案解析】Let the number be x, and write the equation:

Multiply both sides by 12: 9x = 84 + 2x Subtract 2x from each side and divide by 7: 7x = 84 x=12 Be careful: 12 is not the answer. You were asked for

of the number:

单选题 An operation, *, is defined as follows: for any positive numbers a and b. Which of the following is an integer?

A、 (A) 11*5
B、 (B) 4*9
C、 (C) 4*16
D、 (D) 7*4
E、 (E) 9*9

【正确答案】 D

【答案解析】There's nothing to do except check each choice until you find one that works. In ques-tions such as this, it is often faster to start'with E and work towards A. E:

, which is not an integer. D: