Revaluation reserve( Four column approach)

Hello , In the below question when i take the four column approach my reserve in OCI is coming to 50000 but in the solution they have debited asset with 45000? Can you tell how to solve this question using the four column approach? When Ira Vann commenced trading as a car hire dealer on 1 January 20X1, he purchased business premises at a cost of $50,000. For the purpose of accounting for depreciation, he decided the following. (a) The land part of the business premises was worth $20,000; this would not be depreciated. (b) The building part of the business premises was worth the remaining $30,000. This would be depreciated by the straight line method to a nil residual value over 30 years. After five years of trading, on 1 January 20X6 Ira decides that his business premises are now worth $150,000, divided into: $ Land 75,000 Building 75,000 150,000 He estimates that the building still has a further 25 years' useful life remaining. Required (a) Calculate the annual charge for depreciation for the first five years of the building's life and the statement of financial position value of the land and building as at the end of each of the first five years. (b) Demonstrate the impact the revaluation will have on the depreciation charge and the statement of financial position value of the land and building.