SETS 5

If n(A)= 80 , n(B)= 90 and n(AuB)= 166, find n(AnB).

Solution

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

166 = 80 + 90 - n(AnB)

166 = 170 - n(AnB)

166 - 170 = - n(AnB)

-4 = -n(AnB)

n(AnB) = 4 [after dividing by -1 both sides]

Hence n(AnB) = 4 answer

TRY THIS………….

If n(A)= 89 , n(B)= 87 and n(AuB)= 131, find n(AnB).