Question

A car can travel 30 miles on a gallon of gas and had a 20 gallon gas tank. Let g be the number of gallons of gas the car has in its tank. The function d=30g gives the distance d in miles that a car travels on g gallons

Answer 1

The domain is the number of gallons and the range is the distance traveled.

Since the car can travel 30 miles one gallon of gas, we multiply by 12 to get the distance the car can travel in 12 gallons of gas.