You are on your way home after Thanksgiving with the family. You fill the gas tank of your nice new small car, which holds l0 gallons and gives you 25 miles to the gallon. That should get you home easily, as home is 220 miles away. Unfortunately, about 20 miles from home, the car stops, and you discover the tank is dry--obviously a leak, because you can see drops dripping.
How many gallons of gasoline have you lost?