1、GRE（ QUANTITATIVE）综合模拟试卷 14及答案与解析 0 Let A, B, C, and D be events for which P(A or B)- 0.6, PA)= 0.2, P(C or D)= 0.6, and P(C)= 0.5. The events A and B are mutually exclusive, and the events C and D are independent. (a)Find P(B) (b)Find P(D) 2 Lin and Mark each attempt independently to decode a messa
2、ge. If the probability that Lin will decode the message is 0.80 and the probability that Mark will decode the message is 0.70, find the probability that (a)both will decode the message (b)at least one of them will decode the message (c)neither of them will decode the message 5 The table below shows
3、the distribution of a group of 40 college students by gender and class. If one student is randomly selected from this group, find the probability that the student chosen is(a)not a junior(b)a female or a sophomore(c)a male sophomore or a female senior 8 The figure above shows a normal distribution w
4、ith mean m and standard deviation d, including approximate percents of the distribution corresponding to the six regions shown.Suppose the heights of a population of 3,000 adult penguins are approximately normally distributed with a mean of 65 centimeters and a standard deviation of 5 centimeters.(a
5、)Approximately how many of the adult penguins are between 65 centimeters and 75 centimeters tall?(b)If an adult penguin is chosen at random from the population, approximately what is the probability that the penguin s height will be less than 60 centimeters? Give your answer to the nearest 0.05. 10
6、PUBLIC AND PRIVATE SCHOOL EXPENDITURES 1987-2001 (in billions of dollars) (a)For which year did total expenditures increase the most from the year before?(b)For 2001, private school expenditures were approximately what percent of total expenditures? 12 DISTRIBUTION OF WORKFORCE BY OCCUPATIONAL CATEG
7、ORY FOR REGION Y IN 2001 AND PROJECTED FOR 2015(a)In 2001, how many categories each comprised more than 25 million workers?(b)What is the ratio of the number of workers in the Agricultural category in 2001 to the projected number of such workers in 2015 ?(c)From 2001 to 2015, there is a projected in
8、crease in the number of workers in which of the following categories?I. SalesII. ServiceIII. Clerical 15 A FAMILYS EXPENDITURES AND SAVINGSAS A PERCENT OF ITS GROSS ANNUAL INCOME*(a)In 2003 the family used a total of 49 percent of its gross annual income for two of the categories listed. What was th
9、e total amount of the familys income used for those same categories in 2004?(b)Of the seven categories listed, which category of expenditure had the greatest percent increase from 2003 to 2004 ? GRE（ QUANTITATIVE）综合模拟试卷 14答案与解析 1 【正确答案】 0.4 2 【正确答案】 0.2 3 【正确答案】 0.56 4 【正确答案】 0.94 5 【正确答案】 0.06 6 【正确答案】 21/40 7 【正确答案】 7/10 8 【正确答案】 9/40 9 【正确答案】 1,440 10 【正确答案】 0.15 11 【正确答案】 1998 12 【正确答案】 19% 13 【正确答案】 Three 14 【正确答案】 9 to 14, or 9/14 15 【正确答案】 I, II, and III 16 【正确答案】 $17,550 17 【正确答案】 Miscellaneous
