If $A, B$ and $C$ are any three sets,then $A - (B \cap C)$ is equal to

If $A$ and $B$ are disjoint sets,then $n(A \cup B) = $

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

If $A = \{ x : x \text{ is a natural number} \}$,$B = \{ x : x \text{ is an even natural number} \}$,$C = \{ x : x \text{ is an odd natural number} \}$,and $D = \{ x : x \text{ is a prime number} \}$,find $A \cap C$.

If $A = \{1, 2, 3\}$ and $B = \{3, 8\}$,then find $(A \cup B) \times (A \cap B)$.

The simplified switching circuit for the following circuit is