Can't figure out the last part

Henrie's Drapery Service is investigating the purchase of a new machine for cleaning and blocking drapes. The machine would cost $137,320, including freight and installation. Henrie's estimated the new machine would increase the company's cash inflows, net of expenses, by $40,000 per year. The machine would have a five-year useful life and no salvage value. Required: 1. What is the machine's internal rate of return? Note: Round your answer to the nearest whole percentage. 2. Using a discount rate of 14%, what is the machine's net present value? Interpret your results. 3. Suppose the new machine would increase the company's annual cash inflows, net of expenses, by only $31,720 per year. Under these conditions, what is the internal rate of return? Note: Round your answer to the nearest whole percentage