Isabella wishes to buy gasoline and have her car washed. She finds that if she buys 9 gallons of gasoline at $1.50 per gallon, the car wash costs $1, but if she buys 10 gallons of gasoline, the car wash is free. For Isabella, the marginal cost of the tenth gallon of gasoline is

Question

Quizplus · Accepted Answer

The marginal cost of the tenth gallon is the additional cost incurred by purchasing it. Buying 9 gallons costs $13.50 plus $1 for the car wash, totaling $14.50. Buying 10 gallons costs $15 with a free car wash. The difference is 50 cents.

Isabella Wishes to Buy Gasoline and Have Her Car Washed