The Hardluck mining company has an investment opportunity in an open pit mine. As its initial investment, the company would have to spend $5.5 million now to get started, but the government will pay a subsidy now to Hardluck of $15.5 million. Next year, year 1, the company would have to make a further investment of $23.6 million to have the mine ready for exploitation (as usual, assume end-of-period cash flows). Starting in year 2, mining costs are expected to be $1.4 million per year, and revenues are expected to be $3.2 million in year 2, and to increase at a rate of 4% per year after year 2. Hardluck will need to replace some equipment at year 13, at a cost of $18 million. Equipment salvage values at year 25 are zero. Assuming MARR=18%, calculate the IRR of the project in Excel and make sure that there is just one IRR. If not, then calculate the approximate external rate of return