Fill in the blank to make the following statement true: $\varnothing^{\prime} \cap A = \text{?}$

Two dice are thrown. The events $A, B$ and $C$ are as follows:
$A:$ getting an even number on the first die.
$B:$ getting an odd number on the first die.
$C:$ getting the sum of the numbers on the dice $\leq 5$.
Describe the event $A^{\prime}$.

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

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

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

$A$ and $B$ are events such that $P(A)=0.42$,$P(B)=0.48$ and $P(A \cap B)=0.16$. Determine $P(\text{not } A)$.