Question

From the given diagram, find number of elements in (A $\cap$ B)${}^{{}^{\prime }}$

Answer 1

$(A\cap B)$ will have the elements in the intersection of sets $A$ and $B$.
Clearly, $(A\cap B)=$ { $1$ }
Thus ${(A\cap B)}^{{}^{\prime }}$ will have the remaining elements inside $\xi$ except $1$.
$\Rightarrow {(A\cap B)}^{{}^{\prime }}=$ { $2,3,4,5,6,7,8,9,10$ }