SETS 2

If n(A) = 30 , n(AuB) = 60 and n(AnB) =10, find n(B)

Solution

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

  60     = 30 + n(B)  – 10

  60     = 30 -10 + n(B)  

  60     = 20 + n(B)  

  60 - 20        = n(B)

  40        = n(B)

Hence n(B) = 40 answer

TRY THIS…………………………….

If n(A)= 40 , n(AuB) = 70 and n(AnB) = 20, find n(B).