Early in the current year, Tokay Co. purchased the Silverton Mine at a cost of $17,580,000. The mine was estimated to contain 170,000 tons of ore and to have a residual value of $5,000,000 after mining operations are completed. During the year, 155,000 tons of ore were removed from the mine. At year-end, the book value of the mine (cost minus accumulated depletion) is: Multiple Choice $12,580,000 $11,470,000. O $6,110,000. U O $7,580.000