The Marginal cost of product W exhibiting positive externalities is McW = 25 + 5 Qs, the competitive price for each unit of W (Pw) is Rs. 175 and the positive externality is worth Rs. 100 to society for each unit produced. Society considers product W under produced by how many units.
A drop in the price of compact disc shifts the demand curve for prerecord tapes leftward from that you know that compact discs and precorded tapes are.