If a plant asset was purchased on January 1 for $100,000 with an estimated salvage value of $20,000 at the end of its useful life. the current year's depreciation expense is $10,000 calculated on the straight-line basis and the balance of the accumulated depreciation account at the end of the year is $50,000. the remaining useful life of the plant asset is $56,000 due to accumulated depreciation account.