Find the union of each of the following pairs of sets:
$X = \{1, 3, 5\}, Y = \{1, 2, 3\}$

If $U = \{1, 2, 3, 4, 5, 6, 7, 8, 9\}$,$A = \{2, 4, 6, 8\}$ and $B = \{2, 3, 5, 7\}$,verify that $(A \cup B)^{\prime} = A^{\prime} \cap B^{\prime}$.

If $A=\{3, 5, 7, 9, 11\}, B=\{7, 9, 11, 13\}, C=\{11, 13, 15\}$ and $D=\{15, 17\}$,find $A \cap (B \cup C)$.

Let $A$ and $B$ be two sets,then $(A \cup B)' \cup (A' \cap B)$ is equal to

If $A = \{3, 6, 9, 12, 15, 18, 21\}$,$B = \{4, 8, 12, 16, 20\}$,$C = \{2, 4, 6, 8, 10, 12, 14, 16\}$,and $D = \{5, 10, 15, 20\}$,find $A - B$.

Consider the experiment of rolling a die. Let $A$ be the event 'getting a prime number' and $B$ be the event 'getting an odd number'. Write the set representing the event '$A$ but not $B$'.