Burning one gallon of gasoline in a car releases approximately 20 pounds of CO₂ into the atmosphere. One person drives 60,000 miles in a car that averages 30 miles per gallon (mpg), while another person drives 60,000 miles in a car that averages 20 mpg. Over the course of the 60,000 miles, how many fewer pounds of CO₂ are released by the 30 mpg car than by the 20 mpg car?

20,000

Explanation:

In one gallon of gasoline has about 6.3 pounds weight and on burning gives about 20 pounds of carbon dioxide and which is the combined weight of the Oxygen of the air and when this gasoline burns the H and C ions are separated. As Carbon has a weight of 12 and Oxygen has 16, the combined atomic weights will be equal to 44 / 12 = 3.7 pounds and since gasoline is about 87% carbon and has 13% of the hydrogen. Since in the case one the 60,000 miles and 30 miles per gallon and 20 miles per gallon the pounds of carbon are 60,000 miles by the 30 and 20 mpg is equal to 20,000 pounds i.e 5.5 x 3.7 + 30 miles.