SETS E1

 

If n(A)= 55 , n(AuB) = 130 and n(AnB)=30, find n(B)

 

Solution

 

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

 

  130     = 55 + n(B)  – 30

 

  130     = 55 - 30 + n(B) 

 

  130     = 25 + n(B) 

 

  130 - 25        = n(B)

 

  105        = n(B)

 

Hence n(B) = 105 answer

TRY THIS…………………………….

 

 

If n(A)= 62 , n(AuB) = 138 and n(AnB) = 28, find n(B).