Luisa drives 10 miles to the grocery store, 6 miles to the mall, 5 miles to the pet store, then 9 miles back home. One gallon of gas can be used to drive 15 miles. If one gallon of gas costs $3.50, what is the total cost of the gas for Luisa’s entire trip?
Luisa drives a total of 10 + 6 + 5 + 9 = 
<gadget id="calculator">10+6+5+9</gadget>
<output>30</output>
30 miles.
Luisa uses 30 / 15 = 
<gadget id="calculator">30/15</gadget>
<output>2</output>
2 gallons of gas for her trip.
The total cost of the gas for Luisa's trip is 2 * $3.50 = $
<gadget id="calculator">2*3.5</gadget>
<output>7</output>
7.

<result>7</result>