please don't use excel formula

Question: In 2015, Ellie Co. purchased property with natural resources for 28,000,000. The property had a residual value of 5,000,000 However the entity is required to restore the property to the original condition at a discounted amount of 2,000,000. In 2015, the entity spent 1,000,000 in development cost and 3,000,000 in building in 2016, 4,000,000 was spent for additional development of the mine. Production began in 2016 and 3,000,000 tons were extracted in 2016 and 2,500,000 tons in 2017. The remaining tons totaled 7,000,000 and 3,500,000 respectively on December 31, 2016 and 2017. What amount of depletion should be recognised in 2017? A. 10,500,000 B. 12.250.000 9,000,000 D. 8,750,000