Question

Let $O=$ Set of odd natural numbers $=\{1,3,5,7,9,...\}$ and $E=$Set of even natural numbers $=\{2,4,6,8,10,........\}$. Then show that $28\in E$.

Answer 1

$0=\{1,3,5,7,9,.....\}$

$E=\{2,4,6,8,10,......\}$

It is clear from the definition of $E$, $28\in E$