Lizzy: 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?.
Me: Hmmm, let me think. I think this is the detailed solution:
Luisa drives a total of 10 + 6 + 5 + 9 = 30 miles. Luisa uses 30 / 15 = 2 gallons of gas for her trip. The total cost of the gas for Luisa's trip is 2 * $3.50 = $7. Final answer: 7.