FARevaluation reserve

Dear Sir, i review questions from bpp (i-pass) and have a difficulty with the following: 1)At 31 December 20X3 Q, a LLC, owned a building that had cost $800.000 on 1 January 20W4.It was being depreciated at 2% per year. On 31 December 20X3 a revaluation to $ 1.000.000 was recognized. At this date the building had a remaining useful life of 40 years. What is a balance on the revaluation surplus at 31 December 20X3 and the depreciation charge in the P&L for the year ended 31 December 20X4? Answer: Depreciation charge = $2500 Revaluation surplus = (1.000.000 – (800.000 –(800.000 x 2%x10)) = 360.000 I don’t understand why is 10 years for depreciation. 2)Banter Co purchased an office building on 1 January 20X1. The building cost was $1.600.000 and this was depreciated by the straight line method at 2% per year, assuming a 50-year life and nil residual value. The building was revalued to $2.250.000 on 1 January 20X6. The useful life was not revised. The company’s financial year end ends on 31 December. What is the balance on the revaluation reserve at 31 December 20X6? Answer: $810.000 - $18.000 = $ 792.000 There is no word about excess depreciation, is it by default that we should transfer it to ret.earnings ? 3)If we deal with the disposal of a revalued asset: The revaluation reserve will be always transferred to realized profits, but this will not be reported as a profit in the P&L. Is it correct?