SETS - 3

If n(A)= 36 , n(B)= 50 and n(AuB)=65, find n(AnB).

Solution

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

       65 = 36 + 50 - n(AnB)

       65 = 86  - n(AnB)

       65 - 86 = - n(AnB)

      -21 = - n(AnB)

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

Hence n(AnB) = 21 answer

TRY THIS……………………

If n(A)= 35 , n(B)= 45 and n(AuB)=70, find n(AnB).