Answer: This is a ratio of miles (m) per gallon (g), which can be written as the fraction m/g. So Hank's truck can do 68 miles per 4 gallons, or 68/4. The other ration of miles per gallon is 34 miles to (x) amount of gallons. If you set these ratios equal to each other, the resulting equation can help you solve for the number of gallons.