Answer
$\emptyset \in \{\emptyset, \{\emptyset\}\}$ is true.
Work Step by Step
$\emptyset \in \{\emptyset, \{\emptyset\}\}$
This is correct.
Let's say:
$B = \{\emptyset, \{\emptyset\}\}$
$\in$ means that the element to the left is contained in the set to the right.
We can see that $\emptyset$ is contained in $B$.
Therefore, we can say: $\emptyset \in B$
