Please kindly help me with these question ^_^ Thanks

Subject is Asset Management

1. (a) A certain fluidized-bed combustion vessel has an investment cost of $100,000, a life of 10 years, and negligible market (resale) value. Annual costs of materials, maintenance, and electric power for the vessel are expected to total $10,000. A major relining of the combustion vessel will occur during the fifth year at a cost of $30,000. If the interest rate is 15% per year, what is the lump-sum equivalent cost of this project at the present time? (b) A simple, direct space heating system is currently being used in a professional medical office complex. An upgraded "variable air-volume system" retrofit can be purchased and installed for $200,000 (investment cost). Its power savings in the future will be 500,000 kilo-Watt hours per year over its estimated life of 8 years. The cost of electricity is $0.10 per kilo-Watt hour. If the firm's cost of capital is 12% per year and the residual value of the system in 8 years is $20,000, should the new system be purchased? Use the present worth method