SETS B12

If n(A)= 30 , n(B)= 50 and n(AuB)=65, find n(AnB).

Solution

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

       65 = 30 + 50 - n(AnB)

       65 = 80  - n(AnB)

       65 - 80 = - n(AnB)

      -15 = - n(AnB)

15 = n(AnB) (after dividing by -1 on both sides)

Hence n(AnB) = 15 answer

TRY THIS……………………

If n(A)= 33 , n(B)= 46 and n(AuB)=69, find n(AnB).