Question

If $A=\{5,6,7,8\}$ and $B=\{6,8,10\}$ find total elements in $(A\cup B)\times (A\cap B)$.

Answer 1

$A=\{5,6,7,8\}$ and $B=\{6,8,10\}$
$A\cup B=\{5,6,7,8,10\}$
$A\cap B=\{6,8\}$
$(A\cup B)\times (A\cap B)=\{5,6,7,8,10\}\times \{6,8\}$
$\{(5,6),(5,8),(6,6),(6,8),(7,6),(7,8),(8,6),(8,8),(10,6),(10,8)\}$

total elements in $(A\cup B)\times (A\cap B)$ are $10$.