SETS 1

If n(A)= 60 , n(AuB) = 120 and n(AnB)=10, find n(B)

Solution

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

  120     = 60 + n(B)  – 10

  120     = 60 -10 + n(B) 

  120     = 50 + n(B) 

  120 - 50        = n(B)

  70        = n(B)

Hence n(B) = 70 answer

TRY THIS…………………………….

If n(A)= 66 , n(AuB) = 120 and n(AnB) = 30, find n(B).