单选题
Directions: 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?
【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 [*].
**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 a number is 7 more than of the number, what is
【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:[*]
[*]
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?
Which of the following is an integer?
【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: [*] an integer.
Once you find the answer, do not waste any time trying the other choices—they won't work.
E: [*], which is not an integer.
D: [*] an integer.
Once you find the answer, do not waste any time trying the other choices—they won't work.