Hello!
First you have to find how far the car goes with 1 gallon of gas
To find this you do 150/12
150/12 = 12.5
The car goes 12.5 miles for 1 gallon of gas
Next you do how far the car needs to go divided by how far it goes on 1 gallon of gas
500/12.5 = 40
The car needs 40 gallons to travel 500 miles
The answer is 40
Hope this helps!