SETS 3

If n(A)= 60 , n(AuB) = 130 and n(AnB)=10, find n(B)

Solution

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

  130     = 60 + n(B)  – 10

  130     = 60 -10 + n(B) 

  130     = 50 + n(B) 

  130 - 50        = n(B)

  80        = n(B)

Hence n(B) = 80 answer

TRY THIS…………………………….

If n(A)= 68 , n(AuB) = 120 and n(AnB) = 32, find n(B).