An automobile engine that burns gasoline has been engineered to have a relatively high efficiency of 22 %.

An automobile engine that burns gasoline has been engineered  to have a relatively high efficiency of 22 %. While a car is being  driven along a road on a long trip, 14 gallons of gasoline are  consumed by the engine. Of the 14 gallons, how much gasoline  was used in doing the work of propelling the car?