How many pounds of carbon dioxide does she produce per week and per year by commuting with this vehicle?

Question

Twenty pounds of carbon dioxide are emitted into the atmosphere for each gallon of gasoline that is burned in an automobile.  Carbon dioxide is the major greenhouse gas  that contributes to global warming and therefore climate change. An employee commutes to Des Moines, IA from a rural community. She drives an average of 300 miles per week. The vehicle that she drives has a fuel economy rating 25 miles per gallon. 

 

How many pounds of carbon dioxide does she produce per week and per year by commuting with this vehicle?  Assume that she has a five-day workweek and works 50 weeks out of the year

Answer 1

50 wk/yr  x  300 mi/wk  x  1 gal/25 mi x 20 lb/ gal = 12,000 lbs/year of CO2

 

However, since a gallon only weighs 8.3lb, you can't possibly produce 20 lbs of CO2/ gallon of gas.  This breaks the law of conservation of mass, so, you've either copied the problem incorrectly or it's a poorly written problem...