Question

a driver wishes to buy gasoline and have her car washed. she finds that the wash costs $3.00 when she buys 19 gallons at $1.00 each, but that if she buys 20 gallons the car wash is free. Thus, the marginal costs of the 20th gallon of gas is

Answer 1

The total cost for 20 gallons and washing is 19+3 =$22, 19 gallons cost $19.00

The total cost for 20 gallons and washing is 22.

The change in cost is 0.Therefore the marginal cost for the 20th gallon is $0.00