46. You are operating an old machine that is expected to produce a cash inflow of $6,000 in each of the next 3 years before it fails. You can replace it now with a new machine that costs $21,000 but is much more efficient and will provide a cash flow of $11,500 a year for 4 years. Calculate the NPV of the new machine if the discount rate is 15%, 47. Calculate the IRR for this project. 48. What is the Payback Period? 49. Consider the following projects. Calculate the IRR for Project A and Project B. 50. Which project does the IRR rule say is better? 51. Which is really better