The curtis car traveled an average of 21 miles per gallon of gas. At that rate, how far could the car travel on a full tank of 21 gallons
Rate = 21 miles per gallon.
No. of gallons = 21
Distance = Rate x No. of Gallons
= 21 x 21
= 441
Thus, the curtis car can travel 441 miles at the rate of 21 miles per gallon