A special task team of 5 is to be selected randomly from 12 policemen and 8 policewomen. Find the number of ways that the team will consist of
a) 3 men and 2 woman
b) at least 2 men
c) at least 1 woman
F.6 maths(6)
2010-03-31 7:16 am
回答 (2)
2010-03-31 7:28 am
✔ 最佳答案
a) 3 men have 12C3 = 220 ways
2 women have 8C2 = 28 ways
220 x 28 = 6160 ways
b)
The ways of at least 2 men
= All ways - all women ways - 1 man ways
= 20C5 - 8C5 - (12C1)(8C4)
= 15504 - 56 - 840
= 14608 ways
c)
The ways of at least 1 woman
= All ways - All men ways
= 20C5 - 12C5
= 15504 - 792
= 14712 ways
2010-03-31 7:25 am
a) 12c3 x 8c2/ 20c5
b) 1- 8c5/20c5-12c1x8c4/20c5
c)1- 12c5/20c5
我冇計數機係度..自己按吧
b) 1- 8c5/20c5-12c1x8c4/20c5
c)1- 12c5/20c5
我冇計數機係度..自己按吧
收錄日期: 2021-04-21 22:09:14
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20100330000051KK03695