The board of the firm wanted to get value for money by employing the right number of workers. Thus it hired an economist to estimate the firms production function. Based on the economists report, the board now knows that the firms production function is given by:

Capital is fixed at 9 units. Suppose the firm can hire labour at a wage of GHS15 per hour, and output can be sold at a price of GHS500 per unit. Determine the profit-maximising levels of labour and output.