单选题 The revenue from lottery ticket sales is divided between prize money and the various uses shown in the graph labeled "Proceeds." In 1997, what per-cent of the money spent on tickets was returned to the purchasers in the form of prize money?

A、 (A) 23.5%
B、 (B) 50%
C、 (C) 60%
D、 (D) 66%
E、 (E) 74%

【正确答案】 D

【答案解析】The difference between the total ticket sales ($35.5 billion) and the total distribution of the proceeds ($12.0 billion) was the amount returned to the purchasers of lottery tickets in the form of prize money: $35.5 billion -$12.0 billion = $23.5 billion. Divide 23.5 by 35.5 (or approximate, by dividing 24 by 36) to see that 66% of the tick-et sales was allocated to prize money.

单选题 Approximately what percent of the proceeds that went to the states' General fund would have to be given to the senior citizen programs so that the proceeds for the senior citizen programs and the Cities would be equal?

A、 (A) 0.9%
B、 (B) 9%
C、 (C) 31%
D、 (D) 48%
E、 (E) 69%

【正确答案】 C

【答案解析】In order for the amount received by senior cit-izens programs to be the same as the amount received by the Cities, an additional $0.9 bil-lion would have to be allocated to the senior citizens programs: $0.9 billion is approxi-mately 31% of the $2.9 billion currently going to the General fund.

单选题 If x+y=a,y+z=b, andx+z=c, whatisthe average (arithmetic mean) of x, y, and z?

【正确答案】 D

【答案解析】 **Use TACTIC 2, Chapter 11: substitute for the variables. Let x = 1, y = 2, and z = 3. Then the average of x, y, and z is 2. When a = 1 + 2 = 3, b=2+3 =5, andc= 1 + 3 = 4, which of the choices equals 2? Only