1. ## Factorial Proof

Hi everyone,

Can anyone help me prove this factorial, or give me an idea as to why this might be true...

(n¦x) *(m¦t-x) = (n+m¦t)

That is, n choose x times m choose (t-x) is equal to n+m choose t.

2. ## Re: Factorial Proof

Originally Posted by KelvinScale
Hi everyone,

Can anyone help me prove this factorial, or give me an idea as to why this might be true...

(n¦x) *(m¦t-x) = (n+m¦t)

That is, n choose x times m choose (t-x) is equal to n+m choose t.