need answers to these questions please

MC AC H Demand 64. The figure above shows demand and short-run cost curves for a perfectly competitive firm. At its profit-maximizing level of output, the firm's short-run TC is represented by area a. ADFO. b. BGHC. c. BGIO. d. ADGIO. 65 When a perfectly competitive industry is in long-run equilibrium, firms maximize profits, and entry forces the price down a. until all firms with losses leave the industry. b. until each firm can earn acceptable level of economic profit. c. until price becomes tangent to the long-run average cost curve. d. until the long-run average cost curve rises above the demand curve. 66. The entry of firms into a perfectly competitive industry causes the supply curve to a. increase its slope. b. decrease its slope. c. move toward the right. d. move toward the left. 67. Entry by new firms into a perfectly competitive industry a. has no effect on existing firms. b. results in higher output by existing firms in equilibrium. c. results in lower output by existing firms in equilibrium. d. results in no change in the market price or output. 68. Richard Doofus quit his job as an accounting professor to start his own restaurant. He gave up a salary of $50,000 per year and withdrew $100,000 in bank CDs earning 5 percent to buy a building and equipment. In the restaurant's first year it had direct expenses of $75,000 and revenues of $150,000. The restaurant's economic profit was a. $15,000. b. $20,000. c. $75,000