Depreciaor by units-of-activity Method Prior to adjustment at the end of the year the balance in Trucks 5423,900 and the balance in Accumulated Depreciation Trucks $125.080. Details of the subsidiary ledger are as follows: Accumulated Miles Estimated Estimated Depreciation Operated Truck Residual Useful at Beginning During No. Cost Value Life of Muar Year 1 584,500 $12.675 240,000 miles 36,000 miles 2 119.900 14,388 360,000 $23,980 36,000 3 97,000 13,580 204,000 $77,600 20,400 4. 122,500 14,700 290,000 $24.500 34,800