A construction firm can lease a crane required on a project for 3 years for $180,000 payable now, with maintenance included. The alternative is to buy a crane for $240,000 and sell it at the end of 3 years for $100,000. Annual maintenance costs are expected to be $5000 for the first two years and $10,000 the third year (payable at the end of each year). Determine the IRR of the increment of buying the crane leasing the crane. Note: Show the cash flow diagram and the NPW equation use your calculator or Excel to determine IRR.