Question

If n ( A ) = 12 , n ( B ) = 15 and n(A∩ B) = 3 then n(A ∪ B )​

Answer 1

Answer:

n(A∪B)=n(A)+n(B)−n(A∩B)−−−−−−−(1)

Given n(A)=7

n(B)=9

n(A∪B)=14

Substituting in 1

14=7+9−n(A∩B)

⇒n(A∩B)=16−14=2