SETS 1B

If n(A)= 60 , n(B)= 90 and n(AuB)= 130, find n(AnB).

Solution

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

130 = 60 + 90 - n(AnB)

130 = 150 - n(AnB)

130 - 150 = - n(AnB) [after transferring 150 on the left hand side]

-20 = -n(AnB)

n(AnB) = 20 [after dividing by -1 both sides]

Hence n(AnB) = 20 answer

TRY THIS………….

If n(A)= 74 , n(B)= 86 and n(AuB)= 125, find n(AnB).