A power shovel (1

A power shovel (1.5 m3) with a power capacity 300 Hp weights 25 ton using diesel engine works 12 seconds with 100%, 18 seconds with 50% and the rest time of the cycle (1 minute), the equipment works with 25% of the power capacity. Also, the equipment stops working 6 minutes per hour. The lubrication oil capacity is 16 litters and has a period of 120 hours for changing oil. The cost of the fuel 0.8 $/lit., and for the oil 6 $/lit. The average maintenance cost per year is about 5000 $/year. The equipment can be used for 4 years with 1600 hours per year. The driver gets every month 3000 $/month. If the engine power is about 22500 kg, rolling resistance 80 kg/ton. Then the operation cost per year is about: 85780$ 30780$ 9640$ 90780$ 3780$, 70640$