Consider the sets $\phi, A=\{1,3\}, B=\{1,5,9\}, C=\{1,3,5,7,9\}$. Insert the symbol $\subset$ or $\not\subset$ between the pair of sets: $A, \ldots B$.

Write the following set in roster form:
$F =$ The set of all letters in the word $BETTER$

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.

Let $A = \{1, 2, \{3, 4\}, 5\}$. Which of the following statements is incorrect and why? $\{ \{ 3, 4\} \} \subset A$

Show that the set of letters needed to spell "$CATARACT$" and the set of letters needed to spell "$TRACT$" are equal.

Which of the following is a set? Justify your answer.
The collection of all even integers.