Let A= {3, 7, 2}.

Question

List all the subsets of A

Answer 1

maybe you want:
3
7
2
3,7
3,2
7,2

Answer 2

number of subsets for 3 elements
= 2^3 = 8
which would include the null set and the entire set.

So we have to include the null set
{}, and the entire set {3,7,2}