let A = {9,10,11,12,13,15}
in this set number of elements is equal to six.
we have to find how many subsets and proper subsets A have.
for finding number of subsets, we use the formula 2 raise to the power n, where n is the number of elements in the set A which is 6, it means 2⁶ subsets
so, set A have 2⁶ = 64 subsets
and to find the proper subsets use the formula 2ⁿ - 1 = 2⁶ - 1 = 64 - 1 = 63
so, set A have 63 proper subsets.
