Question

If $A\subseteq B,$ then $A-B$ is

• A. $B$
• B. $A$
• C. $\varphi$
• D. $B-A$

Answer 1

Answer: (C)

$\varphi$

Given that $A\subseteq B$. This means that all the elements of $A$ are elements of $B$.

$A-B$ means elements of $A$ which are not elements of $B$.

Since given that $A\subseteq B$, there will be no elements in $A$ which are not elements of $B$.

Hence $A-B=\varphi$.