Question 7. The Eagle Bottle Company estimates that the demand curve for the company' s bottles is: Q=160- (P/40) where P is the price of a bottle and Q is the number sold per month. a) Derive the marginal revenue curve for the firm. [4 marks] b) In what price range is the demand for the firm's product price elastic? [4 marks] c) Ifthe firm wants to maximize its dollar sales volume: what price should it charge? [2 marks]