A market contains a group of identical price-taking firms. Each firm has a marginal cost curve MC(Q) = 2Q, where Q is the annual output of each firm. A study reveals that each firm will produce if the price exceeds $20 per unit and will shut down if the price is less than $20. The market demand curve for the industry is D(P) = 240- P/2. At the equilibrium market price, each firm produces 20 units.
What is the equilibrium market price, and how many firms are in this industry?