Assume a firm is planning to buy some new equipment. Use the following information to figure out the net present value of each investment expenditure and, therefore, how many units of capital (machines) the firm should buy. Assume each machine has a life span of three years. 3. Pk $13,000 MRP of first machine bought- $7,500 MRP of second machine bought-$6,000 MRP. of third machine bought- $5,000 MRP of fourth machine bought$4,000