Thread: Combination

I need to write this expression with one combination number: C(15,3)-C(16,2)=C(n,k) so I need to find n and k
How can i get one from these two without using factorials?

Originally Posted by Serillan

I need to write this expression with one combination number: C(15,3)-C(16,2)=C(n,k) so I need to find n and k
How can i get one from these two without using factorials?

I have though about this question since it was posted.
The way it is written implies the use of Pascal's Identity
.

But that lead nowhere that I can see.

Now .
So I did a rather large computer search on various combinations but found none to equal 335. I thought that finding one might give a clue as to how that identity might apply.