Two set A and B are such that n(A∪B) = 21, n(A' ∩ B')=9, n(A∩B)=7, find n(A∩B)'.

Two set A and B are such that n( $A \cup B$ ) = 21, n( $A^{'} \cap B^{'}$ )=9, n( $A \cap B$ )=7, find n $(A \cap B)^{'}$ .

Match the items on the right to the items on the left.

step 1

step 2

step 3