A building with a cost of $1,800,000 has an estimated residual value of $125,000, has an estimated useful life of 40 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 twenty-eighth year of use?
(c) If at the start of the twenty-ninth year it is estimated that the remaining life is 5 years and that the residual value is $80,000, what is the depreciation expense for each of the remaining 5 years?