Answer:
Net cash flow in year 0 = initial investment + increase in working capital
Net cash flow in years 1 to 9 = income after taxes + depreciation
Net cash flow in year 10 = income after taxes + depreciation + recovery of working capital
the percentage of buyers shifting from regular to diet drink is irrelevant for this project
IRR is calculated using the IRR function in Excel, with the inputs of values being the array of cells containing the net cash flows
IRR = 16.7627%