Toss 5 dice simultaneously . Find the probability that exactly 2 dice face in
same number . ( Show steps if possible )
Probability ( toss dice )
2012-10-17 5:37 am
回答 (1)
2012-10-17 7:12 am
✔ 最佳答案
For 2 among 5 dice face in same number :5C2 * 6C1 = 10 * 6 = 60 ways For other 3 dice face in difference numbers :
5 * 4 * 3 = 60 ways
or 3P3 * 5C3 = 6 * 10 = 60 ways
or 3C3 * 5P3 = 1 * 60 = 60 waysP(E) = (60 * 60) / 6⁵ = 25 / 54
Alternatively :(6/6) (1/6) (5C2) * (5/6) (4/6) (3/6) = 25 / 54
收錄日期: 2021-04-24 23:10:52
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20121016000051KK00521