If $A$ and $B$ are two sets,then $A \cap (A \cap B)^c$ is equal to:

If $A = \{x : x \text{ is a multiple of } 3\}$ and $B = \{x : x \text{ is a multiple of } 5\}$,then $A - B$ is equal to,(where $\bar{B}$ is the complement of set $B$.)

Let $U = \{1, 2, 3, 4, 5, 6\}$,$A = \{2, 3\}$,and $B = \{3, 4, 5\}$. Find $A'$,$B'$,$A' \cap B'$,$A \cup B$,and hence show that $(A \cup B)' = A' \cap B'$.

Let $U$ be the universal set of all the students of Class $XI$ of a coeducational school and $A$ be the set of all girls in Class $XI$. Find $A'$.

If $U = \{a, b, c, d, e, f, g, h\}$,find the complement of the set $D = \{f, g, h, a\}$.

Let $U = \{1, 2, 3, 4, 5, 6, 7, 8, 9\}$,$A = \{1, 2, 3, 4\}$,$B = \{2, 4, 6, 8\}$ and $C = \{3, 4, 5, 6\}$. Find $A^{\prime}$.