Question

Let $A=\{1,2\}$ and $B=\{3,4\}$. Write $A\times B$. How many subsets will $A\times B$ have?

Answer 1

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

Now,

$A\times B=\left\{\right(1,3),(1,4),(2,3),(2,4\left)\right\}$.

Since $A\times B$ contains $4$ elements, so number of subsets of $A\times B$ is $2^4=16$.