Insulation will be made in a building in order to save on heating costs. Thanks to this insulation, energy costs It has been calculated that 9% will be saved. Calculations June 2020 It was made at the beginning. Details of this study are given below. I. Natural gas consumption for heating is made for 7 months, including the months of November and May. ii. 500 m3 in November natural gas consumption and 500 m3 per month for the next 3 months increasing. More 300 m3 in the next 3 months is decreasing. The amount of gas consumed each year is fixed. iii. Natural gas price for 2020 is 1.83 TL / m3 15% increase is expected in June 2021. iv. Monthly interest rate is 1.2%. a. Prepare the cash flow of monthly savings amounts. b. Calculate the present value of the savings (early June 2020).