find the number of ways in which 12 people can be divided into .

find the number of ways in which 12 people can be divided into .
find the number of ways in which 12 people can be divided into three groups consisting of 4,4 and 3 people with one person excluded.
答案是69300
英语人气:976 ℃时间:2019-10-17 08:15:43
优质解答
从12个人里面选4个人放在一组:12C4 = 495 种 
从剩下的8个人里面选4个人放在一组:8C4 = 70 种 
从剩下的4个人里面选3个人放一组:4C3 = 4 种 
一个人被排除在外的选法有:12 种 



总共方法数为 495 x 70 x 4 x 12 / 4! = 69300 
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