Question

If $A=\{1,2,3,4,5\}$ then which of the following is correct?

• A. $3\notin A$
• B. $\left\{2\right\}\in A$
• C. $\varphi \in A$
• D. $4\in A$

Answer 1

The correct option is D $4\in A$

$A=\{1,2,3,4,5\}$
Here, $3$ is an element of the set $\therefore 3\in A$
$\left\{2\right\}$ is not an element of the set $\Rightarrow \left\{2\right\}\notin A$
$\varphi$ is a subset of every set but not an element $\Rightarrow \varphi \notin A$
$4$ is an element of the set $\Rightarrow 4\in A$