Question

If A and B be any two sets where $n(A-B)=8$, $n(A\cup B)=20$ and $n(A\cap B)=6$, then $n(B-A)$ is

• A. 14
• B. 12
• C. 6
• D. 20

Answer 1

The correct option is C

6

We know that,

$n(A\cup B)=n(A-B)+n(B-A)-n(A\cap B)$

$\Rightarrow$ 20 = 8 + n(B-A) - 6

$\Rightarrow$ n (B-A) = 6