Element Math Example 2

Solution

1. 1
   (a) $\emptyset \in B$: the empty set $\emptyset$ is listed as the first element of $B$. True.
2. 2
   (b) $1 \in B$: the number $1$ is not directly listed in $B$; only $\{1\}$ is. False.
3. 3
   (c) $\{1\} \in B$: the set $\{1\}$ is the second element of $B$. True.
4. 4
   (d) $\{2,3\} \subseteq B$: this asks whether every element of $\{2,3\}$ is in $B$. The elements are $2$ and $3$, neither of which is in $B$ (only $\{2,3\}$ is). False.