Question

A , B and C are three sets , n(A)=14 , n(C) =13 , n ( A ∪ B ∪ C ) = 28 , n (A) = n (B) , n (A ∩ B) = 7 , n (B ∩ C) = 4 and n(A ∩ C) = 3.
Find n(A ∩ B ∩ C) ?

Answer 1

Answer:

right but one condition it's wrong