12-30 A chemical company bought a small vessel for $550,000; it is to be depreciated by 10-year MACRS. When requirements changed suddenly, the chemical company leased the vessel to an oil company for 6 years at $100,000 per year. The lease also provided that the oil company could buy the vessel at the end of 6 years for $350,000. At the end of the 6 years, the oil company exercised its option and bought the vessel. The chemical company has a 24% combined incremental tax rate. Compute its after-tax rate of return on the vessel