# Problem with Binomial Coefficients

• January 2nd 2012, 03:10 PM
Marmy
Problem with Binomial Coefficients
Hi everybody,

Has somebody any idea why the following is true....?
Attachment 23171

Which rules are applied here?

Thank you very much for any help!
• January 2nd 2012, 03:25 PM
Plato
Re: Problem with Binomial Coefficients
Quote:

Originally Posted by Marmy
Has somebody any idea why the following is true....? Attachment 23171

Suppose that we have $m\text{ men and }n\text{ women}.$
If we want to select a committee of $k$ can that be done in $\sum\limits_{i = 0}^k {\binom{m}{k-i}\binom{n}{i}$ ways?
• January 3rd 2012, 09:05 AM
Marmy
Re: Problem with Binomial Coefficients
Thanks, very helpful again. I think I understand now!