The market demand curve for mineral water is given by P 15 Q. If there are two firms that produce mineral water, each with a constant marginal cost of 3 per unit, fill in the entries for each of the four duopoly models indicated in the table. (In the Stackelberg model, assume that firm 1 is the leader.)

Model Q1 Q2 Q1 Q2 P 1 2 1 2 Shared monopoly Cournot Bertrand Stackelberg