please solve it with hand not excel

e) The G-Cans project in Tokyo has a piece of equipment that has O&M costs of $300 per year every 3 years, but there is no O&M costs until year 4 and the O\& M costs end in year 25 . The equipment is expected to last 25 years and the annual interest rate is 6% compounded annually. What is the present value of the O&M costs for this piece of equipment? f) Japan (G-Can owner) is looking at another piece of equipment that is expected to have operating and maintenance costs of $400 every 5 years starting in year 5 for the life of the equipment (up to and including year 25). The equipment is expected to last 25 years and the nominal interest rate is 6%. What is the present value of the O&M costs? g) Which piece of equipment should the company buy (1e or 1f )