Steven G
Elite Member
- Joined
- Dec 30, 2014
- Messages
- 14,382
I just saw that r*nCr = n*(n-1)C(r-1) where nCr = # of ways to choose r objects from n objects. I was easily able to prove it to convince myself that it is true.
My question is what does it really say, that is what does this identity mean?
My question is what does it really say, that is what does this identity mean?