Question

For any three sets A, B and C if n(A)=17 n (B)=17, n(C)=17, $n(A\cap B)=7n(B\cap C)=6,n(A\cap C)=5$ and $n(A\cap B\cap C)=2$, find $u(A\cup B\cup C)$.

Answer 1

$n(A\cup B\cup C)=n\left(A\right)+n\left(B\right)+n\left(C\right)-n(A\cap B)-n(B\cap C)-n(C\cap A)+n(A\cup B\cup C)=17+17+17-7-6-5+2=35$