GMAT考试数学辅导04年1月数学总结(三)
2011-09-13 17:57:00   来源：Joozone.Com    双击单词自动翻译

　　58.给出一个柱形图，横坐标是六至十二月的平均每日用电量。 纵坐标是千瓦。 每月头600度电每度$0。14，超过的每度$0。11。 求八月的cost.

　　59.给出一个柱形图，横坐标是working hours,纵坐标是人数。 求working hours 的median.

　　60.DS, 不放回抽样，共有English and Spanish 良种，抽两本，问抽得at least one english book的概率。

　　1)english 与spanish 的比是1：3

　　2)书的总数少于20本

　　61.scientist studies the migration trend of a group of geese. The group contains 30% male geese. Among the geese that later on migrated, 20% are male. What is the ratio of migration factor for male geese to the migration facotr for female geese? (migration factor for sex X = number of migrated individual with sex X/total number of individuals with sex X)

　　Solution: Assume total geese X, of which Y migrated.

　　The answer is simple [(20%Y)/(30%X)]/[(80%Y)/(70%X)] = ...

　　62.Some guy has 6 albums of anthology from which he read one poem at least. All peoms in the albums are different. Did he read more than 6 poems from at least one of the album?

　　a) he has read 22 poems in total.

　　b) the numbers of poems he read from each album are all distinct.

　　Anwser: C

　　63. k, l, m are positive integers, does k has more prime factors than m

　　a) k = 30l

　　b) m = 10^k

　　Answer: C

　　64.sqrt{2sqrt(63) + 2/[8 + 3sqrt(7)]}

　　Answer: 4

　　65.two right cylinders, A and B. radius of A is 2 times radius of B. height of A is half the height of B. If B's radius is x and B's height is y. What is the difference between surface area of A and that of B.

　　Solution:

　　A's suface 2*pi*(2x)^2*(y/2) + pi*2*(2x)*(y/2)

　　B's surface 2*pi*x^2*y + pi*2xy

　　Difference = A's - B's

　　66.三角形, 有图, 一底角60度,另一底角45度角, 45度角所队边长10,求60度角所队边长为多少.

　　答案: 5根号6

　　67.某人去商店买东西,1/2买了a, 1/3 for b, 1/10 for c, and the rest $6 for candy. ask the total.

　　ans: 90