Difficult Probability Question
2014-01-09 8:06 am
5 persons A, B,C, D, E sit randomly around a roundtable. The probability that A does not sit next to B is ____
回答 (1)
2014-01-09 8:18 am
✔ 最佳答案
圖片參考：http://imgcld.yimg.com/8/n/HA00430218/o/20140109001453.jpg
WLOG (Without Loss of Generality), you can fix A first.
Now, there are four seats remaining for four persons.
For B to choose out of the four seats, there are 2 places which satisfy your need (that is, A does not sit next to B).
Therefore, the required probability is 2/4 = 1/2.
收錄日期: 2021-04-11 20:27:02
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20140109000051KK00002