XYZ Co. Purchased a delivery van on January 1 , 2016 for $ 100,000 . At the time of purchased it was estimated that the van would be used for 7 years with a51000 trade - in value . On January 1 2020 the company decided to revise the useful life to 10 years and revise the residual value to 10000. Using straight - line depreciation , determine the book value on January 1 , 2020 and the revised depreciation for 2004. Book value calculation : Revised depreciation calculation :