When creating a subset of 5 elements from 7 elements, order should not matter. Therefore, we use the combination formula over the permutation formula.
The combination formula given n elements total and r elements used is n! / [r!*(n-r)!]. Substituting 7 for n and 5 for r, we get:
7! / (5!*2!) = 7*6 / 2 = 21
21 subsets can be created
