SETS 1

If n(A)= 60 , n(AuB) = 140 and n(AnB)=10, find n(B)

Solution

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

  140     = 60 + n(B)  – 10

  140     = 60 -10 + n(B) 

  140     = 50 + n(B) 

  140 - 50        = n(B)

  90        = n(B)

Hence n(B) = 90 answer

TRY THIS…………………………….

If n(A)= 66 , n(AuB) = 144 and n(AnB) = 31, find n(B).