lizzie612 发表于 2007-11-14 11:18:20

请教关于数据充分性的题应该怎么做啊?

If 2 different representatives are to be selected at random from a group of 10 employees and if p is the probability that both representatives selected will be women, is p > 1/2 ?
(1)   More than  1/2 of the 10 employees are women.
(2)   The probability that both representatives selected will be men is less than 1/10.

A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
D. EACH statement ALONE is sufficient.
E. Statements (1) and (2) TOGETHER are NOT sufficient.

比如这道题~~~我怎么看都不知道怎么做!
请大家指点一下!谢谢!!!

wbly 发表于 2007-11-14 18:31:58

如果从10人中任选2人,P代表2人都是女的,P大于1/2在什么情况下成立?
1.10人中一半以上是女人
2.任选2人都是男的,这种概率小于1/10

解:如果10人中5男5女,那任选2人都是女的,概率为2/9,论断1成立
10人中7女3男,选2女概率约1/2,此时选2男,概率1/15,小于1/10,论断2成立
所以选D

lizzie612 发表于 2007-11-15 11:26:38

换句话说要有学习概率的基础?

lizzie612 发表于 2007-11-15 14:11:41

还有我才看到 答案是E
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