Equipment with a cost of $649,900 has an estimated residual value of $74,800, has an estimated useful life of 27 years, and is depreciated by the straight-line method.

a. Determine the amount of the annual depreciation. $

b. Determine the book value after 12 full years of use. $

c. Assuming that at the start of the year 13 the remaining life is estimated to be 21 years and the residual value is estimated to be $73,000, determine the depreciation expense for each of the remaining 21 years. $