A car can travel 80 miles on 4 gallons of gasoline. If the gas tank, which can hold about 15 gallons. How many miles can the car travel before it runs out gas?
Just solve a simple proportion:
80 miles/4 gallons = x miles/15 gallons
80/4 = x/15
20 = x/15
x = 300
the car can go 300 miles