Question

Let $A$ and $B$ are two finite sets such that $n\left(A\right)=3$ and $n\left(B\right)=4$ then the number of elements in $A\Delta B$.

• A. $2$
• B. $7$
• C. $5$
• D. can not be determined

Answer 1

The correct option is D can not be determined

Now, we have,

$A\Delta B=(A-B)\cup (B-A)$.

But it is impossible to find the number of elements in the set $A\Delta B$ as the sets $A$ and $B$ are not given explicitly.