单选题
If p pencils cost c cents, how many can be bought for d dollars?
【正确答案】
E
【答案解析】Since p pencils Cost c cents, each pencil costs 
cents. By dividing the number of cents we have by , we find out how many pencils we can buy. Since d dollars equals 100d cents, we divide 100d by , which is equivalent to multiplying 100d by 
You will probably prefer the alternate solution below.
**Use TACTIC 2, Chapter 12. Assume 2 pen-cils cost 10 cents. So, pencils cost 5 cents each or 20 for one dollar. So, for 3 dollars, we can buy 60 pencils. Which of the choices equals 60 when p = 2, c = 10, and d = 3? Only 
cents. By dividing the number of cents we have by , we find out how many pencils we can buy. Since d dollars equals 100d cents, we divide 100d by , which is equivalent to multiplying 100d by
You will probably prefer the alternate solution below.
**Use TACTIC 2, Chapter 12. Assume 2 pen-cils cost 10 cents. So, pencils cost 5 cents each or 20 for one dollar. So, for 3 dollars, we can buy 60 pencils. Which of the choices equals 60 when p = 2, c = 10, and d = 3? Only
单选题
Because her test turned out to be more difficult than she intended it to be, a teacher decided to adjust the grades by deducting only half the number of points a student missed. For example, if a student missed 10 points, she received a 95 instead of a 90. Before the grades were adjusted the class average was A. What was the average after the adjustment?
【正确答案】
A
【答案解析】If a student earned a grade of g, she massed (100 -g) points. In adjusting the grades, the teacher decided to deduct only half that number: 
. So the student's new grade was
Since this was done to each student's grade, the effect on the average was exactly the same. The new average was 50 + 
. So the student's new grade was
Since this was done to each student's grade, the effect on the average was exactly the same. The new average was 50 +
单选题
If a square and an equilateral triangle have equal perimeters, what is the ratio of the area of the triangle to the area of the square?
【正确答案】
A
【答案解析】
Use TACTIC 3, Chapter 11. Choose an appropriate number for the common perimeter. Any number will work; but since a triangle has 3 sides and a square has 4 sides, 12 is a good choice. Then, each side of the square is 3, and the area is 32 = 9. Each side of the equilateral[ triangle is 4, and the area is
(KEY FACT J15). The ratio is 
Use TACTIC 3, Chapter 11. Choose an appropriate number for the common perimeter. Any number will work; but since a triangle has 3 sides and a square has 4 sides, 12 is a good choice. Then, each side of the square is 3, and the area is 32 = 9. Each side of the equilateral[ triangle is 4, and the area is
(KEY FACT J15). The ratio is