Question

If $A=\{a,b,c,d\}$ and $B=\{a,b,c\}$, then $A-B=$.

• A. $\varphi$
• B. $\{a-a,b-b,c-c,d\}$
• C. $\left\{d\right\}$

Answer 1

The correct option is C $\left\{d\right\}$

For any two sets $A$ and $B$, we have the difference set $A-B$ to be the set of all those elements of $A$ which are not there in $B$.
Thus, for $A=\{a,b,c,d\}$ and $B=\{a,b,c\}$, we have $A-B=\left\{d\right\}.$