Ben Brink
Posts:
198
From:
Rosenberg, TX
Registered:
11/11/06


RE: Permutation problems
Posted:
May 19, 2012 4:34 AM



Mahesh, Before dealing with that, how did you find 23! permutations not containing "fish"? Thanks. Ben
> Date: Sat, 19 May 2012 02:35:41 0400 > From: discussions@mathforum.org > To: discretemath@mathforum.org > Subject: Re: RE: Permutation problems > > I could make some progress after your reply. I thought of doing it other way round. So now the sets are: > A: Contain fish A=23! > B: Contain rat B=24! > C: Contain bird C=23! > A n B: 21! > A n C: 20! > B n C: 21! > A n B n C: 18! > > A' n B' n C'= Total permutations  (A u B u C) > = 26!(23! + 24! + 23!  21!  20!  21! +18!) > =4.0261.... * 10 ^ 26 > Let me know if this is correct. > Thank you.

