# seemingly simple, but very complicated to solve combination

• Feb 1st 2007, 03:21 PM
cubs3205
seemingly simple, but very complicated to solve combination
Consider a man who wishes to purchase 12 donuts. There are 6 kinds of donuts. How many different combinations of donuts can he purchase?
• Feb 1st 2007, 03:31 PM
Plato
To select k items from n different varieties, there are ${{k+n-1} \choose k}$ ways to do that.
• Feb 1st 2007, 04:35 PM
cubs3205
wow thanks
i have never heard of that formula but it certainly works
• Feb 1st 2007, 05:19 PM
Plato
Quote:

Originally Posted by cubs3205
wow thanks
i have never heard of that formula but it certainly works

Here is the way it works.