With the given data, I can only solve for the depletion cost per unit.
Depletion cost per unit = (Total cost - Salvage Value) / Total Estimated Units available
Total Cost includes the following:
Acquisition: 480,000
intangible development cost: 120,000
restoration cost: 96,000
Salvage value is the amount it can be sold: 192,000
Total estimated units available is the 4,800 tons of coal.
Depletion cost per unit = (480,000 + 120,000 + 96,000 - 192,000) / 4,800
Depletion cost per unit = 504,000 / 4,800
Depletion cost per unit = 105 per ton
In the event that there is a given figure of units extracted, simply multiply the depletion cost per unit by the number of units extracted to get the depletion cost on the extraction.
