Problem 6: Bought machinery on January 1, 2018 for P1,000,000 with a useful life of 8 years with P100,000 residual value and depreciated using the straight line method. In January 1, 2020, the entity estimated that the asset's useful life from the date of acquisition should have been 4 years and the residual value is P40,000. What is the accumulated depreciation on December 31, 2020