Please help with this question. Both parts (A and B)

Question 3 (10 points) Peppa pig and Suzy sheep love rowing their boats gently down the stream. But the river is now polluted with industrial waste which makes a very unpleasant rowing experience for them. Suppose Peppa's demand for river water quality is given by QP : 1 _ 2p where P is Peppal's marginal willingness to pay for river quality. Similarly, Suzy's demand is given by qp = 1 _ 210' Clean river quality can be supplied according to q=p where p is the marginal cost of cleaning the river. a. Graph the aggregate demand for clean river along with individual demands. b. What is the efcient amount of clean river