A perfectly competitive constant cost industry contains a number of firms, each of which has the following long-run total cost function, where q is annual output:
TC = 0.01q3 - 1.2q2 + 101q
The market demand curve for the product is:
Q = 7,000 - 20p
where Q is annual industry sales.
(a) Calculate the long-run equilibrium output of the industry.
(b) How many firms are there in the industry in long run?