#### Explanation:

Subtract the $40.00 from the total $131.00. This will give you the amount that you must earn in addition to the $40.00 to get $131.00.

$131.00-$40.00=$91.00 You must earn an additional $91.00 from work. Divide $91.00 by your hourly wage. This will give the number of hours that you need to work to make the additional $91.00.

$\text{91.00"/("$7.00"/"hr")="13 hr}\$