Suppose that individual demand for a product is given by QD = 1000 - 5P. Marginal revenue is MR = 200 - 0.4Q, and marginal cost is constant at $20. There are no fixed cost.
A. The firm is considering a quantity discount. The $120, and further units can be purchased at a price $80. How many units will the consumer buy in total?
B. Show that this second degree price discrimination scheme is more profitable than a single monopoly price.