If $A = \{ 1, 2, 3, 4, 5 \}$,then what is the number of proper subsets of $A$?

Write the set $\{ \frac{1}{2}, \frac{2}{3}, \frac{3}{4}, \frac{4}{5}, \frac{5}{6}, \frac{6}{7} \}$ in the set-builder form.

Write the following set in the set-builder form: $\{ 3, 6, 9, 12 \}$

Write the set $\{ x : x \text{ is a positive integer and } x^2 < 40 \}$ in the roster form.

Which of the following are examples of the null set?
Set of even prime numbers

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 $\leq 5$.
State true or false: (give reason for your answer)
Statement: $A$ and $B^{\prime}$ are mutually exclusive.