The total revenue function for a firm is given as R = 6q - 3q^2 + 10, where R is the total revenue in millions of cedis and q is the output in thousand units. Determine the level of output that maximizes the firm's revenue and find the maximum revenue. If a firm spends $650 on fixed costs, what is its total cost function if its marginal cost function is MC = 82 - 16q + 1.8q^2?