Revision of Depreciation A building with a cost of $438,750 has an estimated residual value of $87,750, has an estimated useful life of 27 years, and is depreciated by the straight-line method. a. What is the amount of the annual depreciation? Do not round intermediate calculations. $ b. What is the book value at the end of the fifteenth year of use? $ c. If at the start of the sixteenth year it is estimated that the remaining life is 15 years and that the residual value is $18,750, what is the depreciation expense for each of the remaining 15 years