Question

List all the subsets of the following set $B=\{p,q\}$

Answer 1

Given, $B=\{p,q\}$
Subsets of $B$ containing $0$ element $=\varphi$
Subsets of $B$ containing $1$ element $=\left\{p\right\},\left\{q\right\}$
Subsets of $B$ containing $2$ elements $=\{p,q\}$
Therefore, Subsets of $B$ are $\{\varphi ,\{p\},\{q\},\{p,q\left\}\right\}$