please help me with this question am practising for exam thanks

Answer the following questions : A property was purchased on 1 January 200 for $2m (estimated depreciable amount $1m useful economic life 50 years). Annual depreciation of $20,000 was charged from 200 to 204 inclusive and on 1 January 205 the carrying value of the property was $1.9m. The property was revalued to $2.8m on 1 January 205 (estimated depreciable amount $1.35m - the estimated useful economic life was unchanged). Required Calculate the revaluation gain and prepare the journal entry to account for the revaluation and compute the revised annual depreciation charge