Fill in the blanks to make each of the following a true statement:
$A \cup A^{\prime} = \ldots$

Taking the set of natural numbers as the universal set,write down the complement of the following set:
$A = \{ x : x \text{ is an even natural number} \}$

Consider the experiment of rolling a die. Let $A$ be the event 'getting a prime number' and $B$ be the event 'getting an odd number'. Write the set representing the event 'not $A$'.

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

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

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