simple set problem.Why I am wrong? Which set is this picture explaining.


1.$A\cap B\cap C$
2.$(C-A) \cup (C-B)$
3.$(A-C) \cap (A-B)$
4.$C-((C-A) \cup(C-B))$

Our teacher give the answer $4$ but I wrote $1$. What's wrong with my answer?

1 and 4 are the correct answers.  So what's wrong with your answer is that you did't say "1 and 4".
