Pinning Down $A\cap C$

Difficulty: Hard · Topics: Discrete Mathematics, Sets, Venn Diagrams

A, B and C are sets with Asubset B and

n(A)=n(Csetminus B)=3

n(B)=n(Acup C)

n(A'cap B)=4

n(Csetminus B')=3 n(Asetminus C)

How many elements does the set Acap C have?