Microeconomics 20th Edition by McConnell, Sean Flynn, Stanley Brue

Exercise 3

After mining 9,273 tons of coal, Blue Sky Mining's managers note that the marginal cost of mining the next ton of coal would be $40 per ton. They also calculate that the user cost of mining that next ton of coal would be $35. If the market price of coal is $72, should Blue Sky mine an additional ton of coal
A) Yes.
B) No.
C) More information is needed.