First you top off your gas tank in Olympia. You then drive your Hummer to Spokane, traveling 319.4 miles. You fill up your gas tank with 28.68 gallons of premium gasoline that costs $2.89 per gallon. What is your gas mileage in miles per gallon AND how much does it cost to drive just one mile in your Hummer (unit rate of cost per mile) ?

The gas mileage in miles per gallon is 11.14 (Rounding to two decimal places) and the cost to drive just one mile is US$ 0.26 (Rounding to next cent).

Step-by-step explanation:

1. Let's review the information given to us to answer the question correctly:

Distance from Olympia to Spokane = 319.4 miles

Amount of premium gasoline in the tank = 28.68 gallons

Cost per gallon of the premium gasoline = US$ 2.89

2. What is your gas mileage in miles per gallon AND how much does it cost to drive just one mile in your Hummer (unit rate of cost per mile) ?

To answer these two questions we will use the following expressions:

Gas mileage in miles per gallon = Distance from Olympia to Spokane/Amount of premium gasoline in the tank

Substituting with the real values, we have:

Gas mileage in miles per gallon = 319.4/28.68

Gas mileage in miles per gallon = 11.14 (Rounding to two decimal places)

Now, let's answer the second question, this way:

Cost to drive just one mile = Cost per gallon of the premium gasoline/Gas mileage in miles per gallon

Replacing with the real values, we have:

Cost to drive just one mile = 2.89/11.14

Cost to drive just one mile = US$ 0.26 (Rounding to next cent)