If n things sit around a table, what is the possibility of two things sit next to each other? The answer is 2/(n-1).
So V1: 1/3; V2: 1/2
-- by 会员 sdcar2010 (2010/12/25 13:57:04)
跟你做得一样,很激动,不过你的思路怎么那么简单。。。
-- by 会员 zflucy11 (2010/12/25 23:40:54)
I learned it from others . . .
If n people sitting on a table, what is the possibility of 2 persons sitting next to each other?
1) Total possible arrangement of n people on a table = n! / n = (n-1)! 2) Total possible arrangement of n-1 people (assuming those two sitting together would be treated as a single person) = 2* (n-1)! / (n-1) = 2* (n-2)! There is a 2 in the equation because the two persons are not identical.
The possibility of 2 persons sitting next to each other = 2* (n-2)! / (n-1)! = 2/(n-1)