Well since it took 54 gallons of gas to travel 324 miles you would divide 324 by 54 to find out how many miles could go into each gallon which would be 6 miles per gallon of gas so you would know that 186 divided by something would be 6 so you would do 186 divided by 6 instead to find the answer. So 31 gallons of gas are needed to travel 186 miles.
