A company sells a product for $150 per unit. Raw material costs are $40 per unit, labor costs are $56 per unit, shipping costs are $14 per unit and annual fixed costs are $200,000.

a) Determine the profit function P = f(x), where x equals the number of units sold.

b) How many units must be sold in order to earn an annual profit of $750,000?

c) What profit is earned if annual sales are 20,000 units?