SETS 2

If n(A)= 90 , n(AuB) = 140 and n(AnB)=40, find n(B)

Solution

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

  140     = 90 + n(B)  – 40

  140     = 90 - 40 + n(B) 

  140     = 50 + n(B) 

  140 - 50     =  n(B)

  90     =  n(B)

Hence n(B) = 90 answer

TRY THIS…………………………….

If n(A)= 63 , n(AuB) = 146 and n(AnB) = 30, find n(B).