Answer: 20 gallons per hour.
Explanation:
Let be "x" the average number of gallons that the car used in one hour.
You need to analize the information given in the exercise:
1. The total amount of gallons used by the car was:

2. The car consumes that amount in
.
So, to convert the mixed number to a decimal number, you must divide the numerator by the denominator of the fraction and add the result to the whole number part. Then:

Set up the following proportion:

Finally, you must solve for "x" in order to find its value:
