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

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

$A \cap D$

Let $A :\{1,2,3,4,5,6,7\}$. Define $B =\{ T \subseteq A$ : either $1 \notin T$ or $2 \in T \}$ and $C = \{ T \subseteq A : T$ the sum of all the elements of $T$ is a prime number $\}$. Then the number of elements in the set $B \cup C$ is $\dots\dots$

Let $A=\{1,2,3,4,5,6\}, B=\{2,4,6,8\} .$ Find $A-B$ and $B-A$

Which of the following pairs of sets are disjoint 

$\{1,2,3,4\}$ and $\{ x:x$ is a natural number and $4\, \le \,x\, \le \,6\} $

If $A$ and $B$ are sets, then $A \cap (B -A)$ is