Question

Two sets $A,B$ are disjoint if

• A. $A\cup B=\varphi$
• B. $A\cap B\ne \varphi$
• C. $A\cap B=\varphi$
• D. $A-B=\varphi$

Answer 1

The correct option is C $A\cap B=\varphi$

If A and B are disjoint set then there won't be any element common in both,
Hence $A\cap B=\varphi$