If $A$ and $B$ are two sets, then $A \cap(A \cup B)$ equals to

If $A=\{1,3,5,7,9,11,13,15,17\}, B=\{2,4, \ldots, 18\}$ and $N$ the set of natural numbers is the universal set, then $\left(A^{\prime} \cup(A \cup B) \cap B^{\prime}\right)$ is

If $S=\{x \mid x$ is a positive multiple of 3 less than 100 $\}$ and $P=\{x \mid x$ is a prime number less than 20$\}$. Then, $n(S)+n(P)$ is equal to

If $X$ and $Y$ are two sets and $X^{\prime}$ denotes the complement of $X$, then $X \cap(X \cup Y)^{\prime}$ is equal to

The set $\{x \in R: 1 \leq x<2\}$ can be written as ............. .