20. A company is interested in a $30,000 piece of equipment that will have a market value of $5,000 at the end of its seven-year life. If the equipment is expected to increase revenues by $5,000 per year for the first 4 years, then by $2,000 per year for the rest of its life. If the company's MARR is 20% per year, what is the simple payback period for this equipment? a) 3 years b) 4 years c) 5 years d) 6 years e) 7 years