when it set marginal revenue equal to its marginal cost was $60.This is what the firm would earn if it was a monopolist.From part b,profit was $19.20 for firm 1.Firm 1 would therefore be willing to pay up to $40.80 for firm 2. when it set marginal revenue equal to its marginal cost was $60. This is what the firm would earn if it was a monopolist. From part b, profit was $19.20 for firm 1. Firm 1 would therefore be willing to pay up to $40.80 for firm 2