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robertt (陈龙川) 于 (Fri Jan 5 21:12:03 2007) 提到:
If a family has two children and there is a boy in the family, what is the
probability that there is a girl?
我的答案是1/2,有人说2/3,大家怎莫看?
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Columbia (Columbia) 于 (Fri Jan 5 21:18:29 2007) 提到:
讨论过很多次了,考古吧
数学版和job版好像都讨论过了
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hbird (eagle) 于 (Fri Jan 5 23:52:16 2007) 提到:
条件概率, 总共的可能性是1.boy,girl 2.boy,boy 3.girl,boy 所以答案是2/3
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