A special purpose NASA fuel cell requires investment of 80,000 and has no MV at any time.Operating expenses in year k are given by Ck = 15,000 TL + 5,000 TL (k - 2). Obsolescence is reflected in increased operating expenses and is equivalent to 6,000 TL per yearthis expense has not been included in the equation for Ck. a. Determine the economic life of the fuel cell if i = 0%. b. Repeat Part (a) when the 6,000 TL per year is ignored. What can you conclude about the influence of an expense that is constant over time on the economic life?