Hi Tanner!
Great question! The key to solving this problem is organizing the cash flows correctly and understanding the difference between NPV and IRR.
Step 1: Identify the cash flows
Both projects require an initial investment of $40 million.
Project X:
- Year 0: −$40 million
- Years 1–5: +$4 million annually
- Year 6: +$9 million
- Years 7–10: +$14 million annually
Project Y:
- Year 0: −$40 million
- Years 1–5: +$12 million annually
- Year 6: +$1 million
- Years 7–10: +$6 million annually
Notice that we subtract the $5 million machinery overhaul from each project's Year 6 cash flow.
Step 2: Calculate NPV
The formula is:
NPV = Σ [CFₜ / (1 + r)ᵗ]
Here, CF represents the cash flow, r is the discount rate (WACC), and t is the year.
(a) At a 5% WACC:
Project X: NPV = $21.08 million
Project Y: NPV = $28.58 million
(b) At a 10% WACC:
Project X: NPV = $5.29 million
Project Y: NPV = $16.79 million
Both projects have positive NPVs at these discount rates, meaning both are expected to create value.
Step 3: Calculate IRR
IRR is the discount rate that makes a project's NPV equal to zero.
In other words:
0 = Σ [CFₜ / (1 + IRR)ᵗ]
Solving using the cash flows:
(c) IRR assuming a 5% WACC:
Project X: IRR = 12.24%
Project Y: IRR = 21.26%
(d) IRR assuming a 15% WACC:
Project X: IRR = 12.24%
Project Y: IRR = 21.26%
Here's an important distinction: IRR does not change when WACC changes! IRR depends on the project's cash flows, while WACC is used to calculate NPV and evaluate whether the project's return is sufficient.
Which project is better?
Project Y is the stronger investment because it generates more cash earlier, resulting in a higher NPV at both discount rates and a higher IRR.
For perspective, at a 15% WACC, Project X would actually have a negative NPV of $5.42 million, while Project Y would still have a positive NPV of $8.06 million.
My biggest takeaway: NPV tells us how much value a project adds in today's dollars, while IRR tells us the project's percentage return. When comparing mutually exclusive investments, NPV is generally the preferred decision-making tool.
Hope this helps clarify the calculations and, more importantly, the reasoning behind them!
Michael