# [SOLVED] subset quantities

• October 14th 2008, 05:40 AM
[SOLVED] subset quantities
U={1,2,3,4,5,6,7,8,9,10}

How many 5-element subsets does U have?

I know how to calculate total number of subsets but I can't find the formula for this question in my notes. Any help would be greatly appreciated.
• October 14th 2008, 05:49 AM
Plato
Quote:

${10 \choose 5} = \frac {10!} {(5!)(10-5)!}$