A monopolist produces at a constant marginal cost of $5. It faces a market demand curve given by Q=53- P.

a) Calculate the profit-maximizing price and quantity for this monopolist.

b) Suppose there is another identical firm in the market. Calculate equilibrium price and outputs, assuming the firms compete as Cournot duopolists.

c) Calculate equilibrium price and outputs, assuming the firms compete as Stackelberg duopolists.