The firms in a perfectly competitive industry have the cost function c ( q ) = 324 + 8 q + 4 q 2 . (a) Determine when these firms experience increasing, decreasing and constant returns to scale. (b) Find the firms' SR and LR supply curves. (c) Find the industry's SR and LR supply curve assuming the industry currently contains 80 firms. (d) If the current demand curve is 1600 - 100 p = q are firms entering or exiting the industry