Which statement best defines a mathematical sequence?

A sequence is defined by the general term $a_n=\frac{n+1}{2n}$. What are the values of the third term ($a_3$) and the fifth term ($a_5$)?

The sequence $\{5,15,45,135,\cdots \}$ is geometric. What is the explicit formula for the $n$^th term $a_n$?

A researcher increases the dosage of a drug to a test group by a fixed 2 mg each day. The first day the dose is 5 mg. On what day n will the dosage first exceed 50 mg?

Simplify the explicit formula $a_n=3+(-2)\cdot (n-1)$ into standard linear form.

Fill in the missing middle term, $x$, so that the list $8$, $x$, $0$ is an arithmetic sequence.

Which list correctly gives the values of $0!$, $1!$, and $2!$ in that order?

Simplify the expression $\frac{(m+3)!}{m!}$ for integer $m\ge 0$.

A committee of $4$ is to be chosen from $10$ people where order matters for roles (chair, secretary, treasurer, member). Which factorial expression models the number of possible role assignments, and what is the numeric total?

The sequence $2,4,8,16,...$ is best classified as:

Compute the $10$^th term of the geometric sequence with $a_1=81$ and $r=-\frac{1}{3}$.

For the geometric sequence defined by $a_n=6\cdot (\frac{3}{4}{)}^{n-1}$, find the smallest integer $n$ such that .