Question

Let $n(U)=700,n(A)=200,n(B)=300,n(A\cap B)=100$, then $n(A^{\prime }\cap B^{\prime })$ is equal to

• A. 400
• B. 600
• C. 300
• D. None of these

Answer 1

Answer: (C)

$n(A^{\prime }\cap B^{\prime })=n(A\cup B{)}^{\prime }=n(U)-n(A\cup B)$
$=n(U)-[n(A)+n(B)-n(A\cap B)]$
$=700-[200+300-100]=300$