作者debdeb ()
看板Math
标题[机统] 瓮中球的问题
时间Wed Feb 9 22:05:58 2011
Consider k urns Ui, i=1,...,k, each of which contain m white balls and
n black balls. A ball is drawn at random from urn U1 and is placed in urn
U2. Then a ball is drawn at random frm urn U2 and is placed in urn U3 etc.
Finally, a ball is chosen at random from urn Uk-1 and is placed in urn Uk.
A ball is then drawn at random from urn Uk. Compute the probability that
this last ball is black.
请问这题该怎麽下手？
我先试解k=3，但完全归纳不出个头绪来
麻烦指点一下，谢谢！
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