Question

If $n(A)=8, n(B)=6$ and the sets A and B are disjoint, then find $n(A uu B)$.

Answer 1

Given, $n(A)=8$ and $n(B)=6$. A and B are disjoint $implies A nn B=phi$
$implies n (A nn B)=0$
$:. n (A uu B)=n (A)+n(B)-n (A nn B)=8+6-0=14$