If $A = \{1, 2, 3, 4, \dots, 10\}$, then the number of non-empty subsets of $A$ containing only even numbers is

Let $A = \{a, e, i, o, u\}$ and $B = \{a, b, c, d\}$. Is $A$ a subset of $B$? No. (Why?). Is $B$ a subset of $A$? No. (Why?)

Examine whether the following statement is true or false:
$\{a\} \in \{a, b, c\}$

The set $A = \{ x : x \ne x \}$ represents:

Given the sets $A = \{1, 3, 5\}$,$B = \{2, 4, 6\}$,and $C = \{0, 2, 4, 6, 8\}$,which of the following sets can be considered as a universal set for all three sets $A$,$B$,and $C$?

Let $A$ and $B$ be two sets. Then