7. (4.0 points) A monopoly faces a demand curve with two types of consumers: Group A with demand PA = 900 - 1/2 QA and Group B with demand PB = 800-1/8 QB . The firm cost function is given by C(Q) =100Q and MC=100. Suppose the firm cannot price discriminate, and must set a single price for both markets. What inverse demand curve does the monopoly face when both groups are active in the market? ( i.e, the aggregate demand for the case when P