SETS 2

If n(A)= 60 , n(AuB) = 100 and n(AnB)=20, find n(B)

Solution

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

  100     = 60 + n(B)  – 20

  100     = 60 -20 + n(B) 

  100     = 40 + n(B) 

  100 - 40        = n(B)

  60        = n(B)

Hence n(B) = 60 answer

TRY THIS…………………………….

If n(A)= 66 , n(AuB) = 118 and n(AnB) = 23, find n(B).