2. a) The data collected in running a machine, the cost of which is Rs. 60,000, are given below: Year 1 2 3 4 5 Resale value (Rs): 42,000 30000 20400 14400 9650 Cost of spares (Rs.): 4000 4270 4880 5700 6800 Cost of labor (Rs.): 14000 16000 18000 21000 25000 Determine the optimum period for the replacement of the machine. (5) b) The maintenance costs per year and the resale price of machine M whose purchase price is Rs 12000 are given as: Year 2 4 UI 6 7 Maintenance cost (Rs.) 2600 3000 3400 4000 4700 5600 6600 Resale Value (Rs.) 7000 4500 3250 2600 2400 2400 2400