A firm knows that its marginal cost for a product is MC = 3x + 20, that its marginal revenue is MR = 44 - 5x, and that the cost of production of 80 units is $11,400.
(a) Find the optimal level of production.
(b) Find the profit function.
(c) Find the profit or loss at the optimal level.
Cost, revenue, and profit are in dollars and x is the number of units.