A city water and waste-water department has a four-year-old sludge pump that was initially purchased for $65,000. This pump can be kept in service for an additional four years, or it can be sold now for $30,000 and replaced by a new pump. The purchase price of the replacement pump is $48,500. The projected MVs and operating and maintenance costs over the four-year planning horizon are shown in the table that follows. Assuming the MARR is 10%, (a) determine the economic life of the challenger and (b) determine when the defender should be replaced. Defender Challenger Year MV at EOY 0&M Costs Marginal Cost MV at EOY O&M Costs EUAC $26,000 $24,500 $31,500 $33,625 $11,000 $31,825 23,000 26,000 31,600 25, 125 12,500 28,272 AWN - 20,000 27,500 32,800 16,625 14,000 27,287 17,000 29,000 34,000 8,125 15,500 26,937 Click the icon to view the interest and annuity table for discrete compounding when the MARR is 10% per year. - X a. The economic life of the challenger is year(s). (Round to the nearest whole number.) More Info b. The defender should be O A. replaced now Discrete Compounding; i= 10% O B. kept for at least one more year Single Payment Uniform Series Compound Compound Sinking Capital Amount Present Amount Present Fund Recovery Factor Worth Factor Factor Worth Factor Factor Factor To Find F To Find P To Find F To Find P To Find A To Find A Given P Given F Given A Given A Given F Given P FIP PIF FIA PIA AIF A/P 1.1000 0.9091 1.0000 0.9091 1.0000 1.1000 1.2100 0.8264 2.1000 1.7355 0.4762 0.5762 1.3310 0.7513 3.3100 2.4869 0.3021 0.4021 JAWN 1.4641 0.6830 4.6410 3.1699 0.2155 0.3155 1.6105 0.6209 6.1051 3.7908 0.1638 0.2638