Answer:
The internal rate of return (IRR) on the machine is closest to 15%
Explanation:
We can use excel to calculate IRR as file attached. And IRR of this project is 15%
Or we can calculate NPV of this project with discount rate to make NPV = 0
NPV = PV of investment + PV of all cash flow in 12 years = 0
PV of investment = $162,600
PV of cashflow = 30,000/(1+ IRR)^ year = 30,000/(1+ IRR)^1 + 30,000/(1+ IRR)^2 +…… +30,000/(1+ IRR)^12