PP-T1-PS75

[小花]

75. 8939-!-item-!-187;#058&006136
A certain law firm consists of 4 senior partners and 6 junior partners. How many different groups of 3 partners can be formed in which at least one member of the group is a senior partner? (Two groups are considered different if at least one group member is different.)

(A) 48
(B) 100
(C) 120
(D) 288
(E) 600

Ans:B

[Huang Hsin-Yi]

全部團體 - 3個都是junior的團體=至少有一位senior的團體組合

所以
C(10,3)-C(6,3)=120-20=100

[小花]

感謝 Huang Hsin-Yi大大的回覆




senior好像是年長, 高年級,進階的意思

[Huang Hsin-Yi]

哇 抱歉!
腦袋想成別的案例!!
(因為我是看男生女生的案例才會解這題)

多謝提醒 已修正