The only input a janitorial service firm uses to clean offices is workers, who are paid a wage, w, of $8 an hour. Each worker can clean four offices...

The only input a janitorial service firm uses to clean offices is workers, who are paid a wage, w, of $8 an hour. Each worker can clean four offices in an hour. Is the firm's input a fixed or variable input? Explain. Determine the total cost (TC), the average total cost (ATC), and the marginal cost (MC) of cleaning offices. There are ten offices 0-10.