The estimated cost of operating and maintaining the machines used by a chemical industry is Rp 6 million in the first year, Rp 6,5 million in the second year and thereafter, it always increases by 0,5 million every year until year 5. If the interest rate which applies is 15% per year, calculate: a. Present value of all costs (in year 0) b. Value all fees by year 5 c. The value of the series is uniform for all these costs for 5 years