A car goes from city "x" to city "y" at an average speed of 77 miles/h. The efficiency of the car is 23 km/liter. The trip went smoothly in 5 hours and 40 minutes. If the car's tank has a capacity of 10 gallons, calculate

a) the percentage of fuel expended, assuming that the tank was full when the trip began.

b) The mass (pounds) of fuel consumed, assuming that the density of the fuel is 0.87g/cm3.