#### Answer

If a person saves weekly and saves $\$10$ during the first week, and increases the amount he/she saves each week by $\$5$, then the amount of money that he/she saves on any given week $n$ is given by the arithmetic sequence
$a_n=10+5(n-1)$

#### Work Step by Step

There are a number of situations in real life that can be modeled by an arithmetic sequence.
One example is when a person decides to save weekly and increases the amount he saves each week by a certain fixed amount.
If a person decides to save weekly, starts with $\$10$ during the first week, and increases the amount he/she saves each week by $\$5$, then the amount that he needs to save on any given week $n$ is modeled by an arithmetic sequence with:
$a_1=\$10$
$d=\$5$
The amount (in $\$$) that he/she needs to save on week $n$ is given by the formula:
$a_n=10 + 5(n-1)$