Question 2 [Total 15 marks] For a replacement analysis, the cost of a challenger is $ 10,000 and the current market value of the defender is $ 2,200 Given that the MARR is 10% per year. The market values (MV) and the annual operating and maintenance costs (AOC) are listed as follows. EOY Defender MV ($) AOC ($) 1000 1000 Challenger MV ($) AOC ($) 3000 0 2000 1500 1 2 500 3000 3 0 6000 1000 3000 4 0 8000 500 6000 (a) Find the economic life (minimum EUAC) of the challenger. (b) Find the most economical period to keep the defender before replacing by the challenger