CHAPTER 5 –
Project C = Project A + Project B
Using a spreadsheet, financial calculator, or trial and error to find the root of the equation, we
find that:
c. The correct decision rule for an investing-type project is to accept the project if the discount
rate is below the IRR. Since there is one IRR, a decision can be made. At a point in the future,
the cash flows from Project A will be greater than those from Project B. Therefore, although
27. To answer this question, we need to examine the incremental cash flows. To make the projects
equally attractive, Project Billion must have a larger initial investment. We know this because the
subsequent cash flows from Project Billion are larger than the subsequent cash flows from Project
Million. So, subtracting the Project Million cash flows from the Project Billion cash flows, we find
the incremental cash flows are:
Incremental
Year cash flows
Now we can find the present value of the subsequent incremental cash flows at the discount rate, 12
percent. The present value of the incremental cash flows is:
28. The IRR is the interest rate that makes the NPV of the project equal to zero. So, the IRR of the
project is:
Even though it appears there are two IRRs, a spreadsheet, financial calculator, or trial and error will
not give an answer. The reason is that there is no real IRR for this set of cash flows. If you examine
the IRR equation, what we are really doing is solving for the roots of the equation. Going back to
high school algebra, in this problem we are solving a quadratic equation. In case you don’t
remember, the quadratic equation is:
2