3. (a) Suppose a perfectly competitive firm has the following total cost function for the short run: STC =100+100Q +5Q' + = Q: 3 Determine its profit-maximizing output and profit for the short run, given the market price of its product is P=$300 per unit. (b) Now disregard the proceeding cost function, and suppose its long-run total cost is: LTC =54Q -2.4Q3 +0.03Q3 Indicate the firm's long-run price, quantity sold, and profit, assuming the industry is in long-run equilibrium