I need help doing number 12 part c, but we can't use excel. We have to show all our work.

12. NPV/IRR. A new computer system will require an initial outlay of $20,000, but it will increase the firm's cash flows by $4,000 a year for each of the next eight years. ( LOS-1) a. Is the system worth installing if the required rate of return is 9% ? b. What if the required return is 14% ? c. How high can the discount rate be before you would reject the project? 13. NPV/IRR. Here are the cash flows for a project under consideration: ( LOS-1 and () LO8-2)