Analyze the two following situations for firms in competitive markets:
a. Suppose that TC=100 + 15q, where TC is total cost and q is quantity produce. What is the minimum price necessary for this firm to produce any output in the short run?
b. Suppose that MC=4q, where MC is marginal cost. The perfectly competitive firm maximizes profits by producing 10 units of out output.
At what price does it sell these units?