Jack drives an 18 wheeler. The truck's gas tank holds 105 gallons of gasoline. The driver begins the trip with a full tank.
Tank holds 105 gallons
65% of gasoline is 0.65 * 105 = 68.25
so 68.25 gallons left in the tank
Tank holds 105 gallons and left out with 68.25 gallons
So gasoline used = 105 - 68.25= 36.75
36.75 gallons of gasoline used