We can start by figuring out how much he traveled per gallon. To do so all we need to do is divide the amount of miles he drove by the gallons it took him to drive that distance (348/12). This comes out to 29 miles. THerefore he drives 29 miles per gallon of gasoline.
Now to find how far he traveled with 8 gallons we need to multiply 29 times 8 (miles per gallon times how many gallons he used)
