Fill in the blank to make the following a true statement:
$U^{\prime} \cap A = \ldots$

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

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

If $A$ is any set,then:

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 $A'$.

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