Question

Given n(A-B)=18, n(AuB)=70 and n(AnB)=25. Find n(B) show your work

Answer 1

Given, n(A - B) =18, n(A∪B) =70, n(A n B) =25

            So, n(A) - (AnB) = 18

              n(A) = n(A-B) + n(AnB)

                      = 18 +25

                      = 43

n(A) + n(B) - n(AnB) = 70

= 43 + n(B) - 25 = 70

 n(B) - 25 = 70 -43

n(B) = 25 +27

       = 52.


Hope this helps!