Let n(A)=32, n(B)=32, n(A?B)=42. Find n(AnB)

Question

Let n(A)=32, n(B)=32, n(A∪B)=42.
Find n(A∩B)

Answer 1

In this set up,

the value for n(A∩B) is not zero because  n(A)+n(B) > n(A U B). 

Therefore, 

n(A U B)= n(A)+n(B)-n(A∩B) 

         42 =  32 + 32 - n(A∩B)

    n(A∩B) = 64 - 42 = 22

Answer 2

22?

32+32-42=22