7. Firm X, operating in a perfectly competitive market, can sell as much or as little as it wants at the market price. The firm's total cost function is TC = 600 + 8Q + 6Q 2 and MC = 8 + 12Q. a. At a market price of $140 per unit, what is the firm's profit maximizing quantity? What is their profit? b. At a market price of $80 per unit, will the firm stay in business in the short-run? If so, what quantity would they produce and what would be their profit?