The cash flow associated with making self-locking fasteners is shown below. Determine the net present worth (year 0) at an interest rate of 10% per year.
Year 0 1 2 3 4 5 6 7 8 9
Income, $1000 20 20 20 20 30 30 30 30 30 30
Cost, $1000 8 8 8 8 12 12 12 12 12 25.
What is the rate of return for this cashflow?