You are shopping for a new car. Compare the volume of carbon dioxide gas emitted by a luxury sedan and a Hummer during a 265 miles trip, if the weatherman reported a temperature of 28°C and an atmospheric pressure of 732 mm Hg. The car dealer claims than the fuel efficiency is 31.2 miles per gallon of gasoline for the luxury car, 10.5 miles per gallon of gasoline for the Hummer. The major component of gasoline is octane (C8H18) which has a density of 0.71 g/mL.