Greg Maddox Company constructed a building at a cost of $2,200,000 and occupied it beginning in January 2001. It was estimated at that time that its life would be 40 years, with no salvage value. In January 2021, a new roof was installed at a cost of $300,000, and it was estimated then that the building would have a useful life of 25 years from that date. The cost of the old roof was $160,000. Instructions a. What amount of depreciation should have been charged annually from the years 2001 to 2020? (Assume straight-line depreciation.) b. What entry should be made in 2021 to record the replacement of the roof? c. Prepare the entry in January 2021 to record the revision in the estimated life of the building, if necessary. d. What amount of depreciation should be charged for the year 2021?