SETS B6

If n(A)= 60 , n(B)= 70 and n(AnB)=40, find n(AuB).

Solution

n(AuB) = n(A) + n(B) - n(AnB)

             = 60 + 70 – 40

             = 130 – 40

             = 90

Hence n(AuB) = 90 answer