Question 1050210


A={13,14,15,16,17,19,20,21}->{{{n(A)=8}}}
There are {{{8}}} elements in a set. The number of subsets for the set are {{{2^n}}} and the number of proper subsets for the set are {{{2^n - 1}}} 

Solution:
A has 

{{{2^n=2^8=256}}} subsets

A has 

{{{2^n-1=2^8-1=256-1=255}}} proper subsets