Revision of Depreciation A building with a cost of $112,500 has an estimated residual value of $22,500, has an estimated useful life of 9 years, and is depreciated by the straight-line method. a. What is the amount of the annual depreciation? $ b. What is the book value at the end of the fifth year of use? $ c. If at the start of the sixth year it is estimated that the remaining life is 5 years and that the residual value is $2,500, what is the depreciation expense for each of the remaining 5 years? $