国际顶尖MBA申请交流平台--TOPWAY MBA

标题: TT-GWD-2-31 [打印本页]

作者: friend_friends 时间: 2007-12-8 06:50 标题: TT-GWD-2-31

Q31:

There are 8 magazines lying on a table; 4 are fashion magazines and the other 4 are sports magazines. If 3 magazines are to be selected at random from the 8 magazines, what is the probability that at least one of the fashion magazines will be selected?

A. 1/2

B. 2/3

C. 32/35

D. 11/12

E. 13/14

答案是E, 请问解题思路？

作者: friend_friends 时间: 2007-12-11 20:14

如果把at least 换成 only 呢……？

作者: kenisjacque 时间: 2007-12-12 06:24

只要算出全部不选fashion magazines 的概率,即全部选 sports magazines.的概率为C(4,3)/C(8,3)=1/14

用1减去一个都不选的概率,即1-1/14=13/14

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