## zarkam21 one year ago Help :]

1. zarkam21

2. anonymous

The number of r-combinations of a set with n elements, where n is a non negative integer and r is an integer with 0<=r<=n

3. anonymous

$C(n,r)=\frac{ n! }{ r!(n-r)! }$

4. anonymous

21

5. zarkam21

21 ways?

6. anonymous

yup @zarkam21