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[组合] 求助!和同事答案不一样!不知谁的对

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word3000 Posted 2016-6-13 21:09 |Read mode
将12个小球(6黑6白)排成一行,从左第一个小球向右数小球,无论数几个小球,黑球的个数总不少于白球个数,则不同的排列数有几种?

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阿鲁 Posted 2016-6-13 21:13
往下看几个帖就有了:forum.php?mod=viewthread&tid=4099
按那帖里的结果,是 $C_{12}^6-C_{12}^5=132$

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 Author| word3000 Posted 2016-6-14 09:50
谢谢

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