If motorists gain $8 in benefits when carbon monoxide emissions are reduced from 10 pounds to 9 pounds and $5 when they are reduced from 9 pounds to 8 pounds, the marginal cost of the 9th pound of carbon monoxide is:

Question

Quizplus · Accepted Answer

The marginal cost of the 9th pound of carbon monoxide is equal to the additional cost incurred to reduce the emissions from 9 pounds to 8 pounds. Since motorists gain $5 when emissions are reduced from 9 to 8 pounds, the additional cost of reducing emissions by another pound must be $5. Therefore, the answer is (B) $5.

If Motorists Gain $8 in Benefits When Carbon Monoxide Emissions