Final answer:
Garth got 30 miles per gallon by dividing the number of miles he traveled, 360, by the number of gallons he used, 12.
Step-by-step explanation:
To calculate miles per gallon (mpg), divide the number of miles traveled by the number of gallons used. In this case, Garth traveled 360 miles and used 12 gallons of gasoline. The formula for mpg is:
Miles per Gallon (mpg) = Total Miles Traveled ÷ Gallons of Gasoline Used
Plugging in the values we have:
mpg = 360 miles ÷ 12 gallons = 30 miles per gallon
Therefore, the correct answer to how many miles per gallon Garth got for his journey is 30 miles/gallon, which corresponds to option C).