SETS 1

If n(A)= 90 , n(AuB) = 140 and n(AnB)=10, find n(B)

Solution

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

  140     = 90 + n(B)  – 10

  140     = 90 -10 + n(B) 

  140     = 80 + n(B) 

  140 - 80        = n(B)

  60        = n(B)

Hence n(B) = 60 answer

TRY THIS…………………………….

If n(A)= 64 , n(AuB) = 148 and n(AnB) = 36, find n(B).