Question

Find total number of subsets of A = {5, 7}

Answer 1

Subsets of a set can be formed by choosing no elements to one or more elements from the set.

If a set contains $‘n^{\prime }$ elements, then the number of proper subsets of the set is $2^n-1.$

If $A=\{p,q\}$ the proper subsets of $A$ are $\left[\right\{\},\{p\},\{q\left\}\right]$

⇒ Number of proper subsets of A are $3=2^2-1=4-1$

Hence, all the Subsets of $A=\varphi ,\left\{5\right\},\left\{7\right\},\{5,7\}$.