Trek Industries purchases new machinery to replace some of its old machinery. The new machinery costs $250,000, has a useful life of 15 years, and has a salvage value of $40,000. Trek sells the old machinery for $30,000. The payback period for the initial investment in the new machinery is exactly 8 years. What is the simple rate of return on the investment in the new machinery? Round to one decimal point. 5.4% 6.1% 7.8% 9.5% None of the above