1. Suppose demand for a good is Q_D = 100 - P and supply is Q_S = -20 + P. This good is sold in a perfectly competitive market.
   1. What is the equilibrium price and quantity (5 points)
   2. What is consumer surplus (5 points)
   3. What is the marginal revenue equation if this was a firm with market power (5 points)
   4. If the supply curve = marginal cost curve , what output would a firm with market power produce and how much would it charge? (20 points)