solve briefly and correctly

The maintenance engineer for a large construction company is examining alternative open to him for replacement of hydraulic on the firm's 100 front-end loaders ; each loader uses six hoses which from historical maintenance records fall at this rate: Month: 1 2 3 4 5 % required replacement by that month: 10 15 20 70 100 The maintenance engineer learns that in the field replacement cost Rs. 80 per hose while it cost only Rs. 40 per hose if all the hose were replaced at regular intervals during routine maintenance and service. Evaluate the alternative open to this engineer and recommend a course of action. The maintenance engineer for a large construction company is examining alternative open to him for replacement of hydraulic on the firm's 100 front-end loaders ; each loader uses six hoses which from historical maintenance records fall at this rate: Month: 1 2 3 4 5 % required replacement by that month: 10 15 20 70 100 The maintenance engineer learns that in the field replacement cost Rs. 80 per hose while it cost only Rs. 40 per hose if all the hose were replaced at regular intervals during routine maintenance and service. Evaluate the alternative open to this engineer and recommend a course of action