回复：If the total people is 7, what is the number of 3+4 part? Is

来源: 于 2012-05-05 10:04:16 [旧帖] [给我悄悄话] 本文已被阅读：次

C(7,3)(4!/4)(3!/3)+7!/7=1140.

8 P, C(8,3)(5!/5)(3!/3)+C(8,4)/2!(4!/4)^2+8!/8, please note 2 and 2!.