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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 of the 10 employees are women.
(2)The probability that both representatives selected will be men is less than 1/10.
E.
C(2,女) / C(2,10) = P推出单独1不可以,女生是6或7时P会小于二分一,大于7个时就可以大于二分一;C(2,男) / C(2,10) <1/10推出单独2也不可以,男的可能出现3个时女的就有7个则小于二分一,但男的出现2个时女的就有8个则大于二分一。两个结合情况一样不可以! 这一题我最后是算出来了,可是花了巨长时间,有没有简单算法?
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