单选题 Questions 3-5 refer to the following graphs.

单选题 If there were 10,000,000 college students in 1975, how many more male students were there than female students?

A. 800,000
B. 1,600,000
C. 2,400,000
D. 4,600,000
E. 5,400,000

【正确答案】 A

【答案解析】From the top graph, we see that in 1975, 54% (35% + 19%) of all college students were male, and the other 46% were female. So there were 5,400,000 males and 4,600,000 females—a difference of 800,000.

单选题 In 1975 what percent of female college students were at least 25 years old? A. 14%B. 30%C. 45% D. 69%E. 76%

【正确答案】 B

【答案解析】In 1975, of every 100 college students, 46 were female—32 of whom were less than 25 years old, and 14 of whom were 25 years old and over. So, 14 of every 46 female students were at least 25 years old. Finally, [*]

单选题 If the total number of students enrolled in college was 40% higher in 1995 than in 1975, what is the ratio of the number of male students in 1995 to the number of male students in 1975?

A. 5:6
B. 6:7
C. 7:6
D. 6:5
E. 7:5

【正确答案】 C

【答案解析】From the two graphs, we see that in 1975 54% (35% + 19%) of all college students were male, whereas in 1995 the corresponding figure was 45% (28% + 17%). For simplicity, assume that there were 100 college students in 1975, 54 of whom were male. Then in 1995, there were 140 college students, 63 of whom were male (45% of 140 = 63). So the ratio of the number of male students in 1995 to the number of male students in 1975 is 63:54 = 7:6.