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

Taking the set of natural numbers as the universal set,write down the complement of the following set:
$A = \{ x : x \text{ is a natural number divisible by } 3 \text{ and } 5 \}$

The number of subsets of $\{1, 2, 3, \ldots, 9\}$ containing at least one odd number is

Let $U$ be the universal set and $A \cup B \cup C = U$. Then $\{ (A - B) \cup (B - C) \cup (C - A)\} '$ is equal to

Taking the set of natural numbers as the universal set,write down the complement of the following set:
$A = \{ x : x \in N \text{ and } 2x + 1 > 10 \}$

Let $A$ and $B$ be two non-empty subsets of a set $X$ such that $A$ is not a subset of $B$,then