1.A model class has 5 men and 4 women . Thetutor wants to select 3 men and 2 women to take part in an advertisement. Modelsin the advertisement will line up in a row, where the men will stand on oneside while the women will stand on the other side, to take photo. Q:Joseph and Josephine are students in themodel class. Find the probability that they will be selected and will standnext to each other in the photo.
Maths and sta question 求救 20點
2011-06-16 3:27 am
回答 (1)
2011-06-16 9:27 am
✔ 最佳答案
1.P(they are selected)
= (3/5) x (2/4)
= 3/10
Man Man Man Woman Woman
Number of ways of line up in a row
= 3P3 x 2P2
= 3! x 2!
= 12
If they stand next to each other, the line would be
Man Man Joseph Josephine Woman
Number of ways that they stand next to each other
= 2P2 x 1P1 x 1P1x 1P1
= 2 x 1 x 1 x 1
= 2
P(they stand next to each other)
= 2/12
= 1/6
P([they are selected] and [they stand next to each other])
= (3/10) x (1/6)
= 1/20
參考: andrew
收錄日期: 2021-04-13 18:01:48
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20110615000051KK00893