Question

Let $A=\{1,2,3,4\}$ and $B=\{2,4,5,6\}$. Find $A\cap B$

Answer 1

Given $A=\{1,2,3,4\}$ and $B=\{2,4,5,6\}$

Note that the only common elements to $A$ and $B$ are $2,4$.

In the Venn diagram, the shaded portion represent $A\cap B$.
Observe that $A\cap B=B\cap A$. Thus intersection is a commutative operation.

Hence, $A\cap B=\{2,4\}$.