Question

If n(a):12,n(a intersection b):5 then find n(a-b)

Answer 1

Answer:

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

n(A∪B) = n(A - B) + n(A ∩ B) + n(B - A) 

   70 = 18 + 25 + n(B - A) 

     70 = 43 + n(B - A) 

     n(B - A) = 70 - 43 

      n(B - A) = 27 

Now n(B) = n(A ∩ B) + n(B - A) 

        n(B)  = 25 + 27 

          n(B)   = 52 

Answer 2

Answer:

7

Step-by-step explanation:

I assume you wanna find n(a-b).

n(a-b) = n(a) - n(a intersection b) = 12 - 5 = 7