Salvage value is 10% per unit cost. Installation cost is P 10,000 for each unit. If the cost of power in the area is P 8.8 per kW-hr and assuming the pumps work alternately in 24 hours, how many hours per year would the motor have to be operated at full load for them to be equally economical? If the expected number of hours of operation per year exceeds the break-even point, which motor is economical? Money is worth 15%.  

The 5-hp electric motor used in the 23 m/hr capacity duplex booster pump to maintain the water supply pressure of a high rise building was burnt-out and considered immediate replacement. Two options were available: A B Original Cost P 90,000 P 120,000 Life, years 13 15 Efficiency 90% 93% Taxes and Insurance P 1,500 P 1,750 Annual Maintenance Cost P 15,000 P 12,000