A Duopoly Example Price and Quantity Supplied The price of water in a perfectly competitive market would be driven to where the marginal cost is zero: P=MC=$O Q=120 gallons The price and quantity in a monopoly market would be where total profit is maximized P=$60 Q=60 gallonsA Duopoly Example: Price and Quantity Supplied • The price of water in a perfectly competitive market would be driven to where the marginal cost is zero: – P = MC = $0 – Q = 120 gallons • The price and quantity in a monopoly market would be where total profit is maximized: – P = $60 – Q = 60 gallons