SETS 5

If n(A)= 70 , n(B)= 90 and n(AuB)= 130, find n(AnB).

Solution

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

130 = 70 + 90 - n(AnB)

130 = 160 - n(AnB)

130 - 160 = - n(AnB)

-30 = -n(AnB)

n(AnB) = 30 [after dividing by -1 both sides]

Hence n(AnB) = 30 answer

TRY THIS………….

If n(A)= 71 , n(B)= 88 and n(AuB)= 130, find n(AnB).