Captain avenger backpacks are the most popular holiday gifts among kids these days. the backpacks are produced by a profit maximizing monopolist. the marginal cost of producing the Qth backpack is $3Q. There are no fixed costs. Demand for the backpack is given by P=1000 - Qd. Now suppose the gov passes a law setting the price of a backpack at $750. What is the quanity the monopolist will choose to maximize profits.