Buffalo mining company purchased land on february 1, 2020, at a cost of $885,500. it estimated that a total of 55,200 tons of mineral was available for mining. after it has removed all the natural resources, the company will be required to restore the property to its previous state because of strict environmental protection laws. it estimates the fair value of this restoration obligation at $103,500. it believes it will be able to sell the property afterwards for $115,000. it incurred developmental costs of $230,000 before it was able to do any mining. in 2020, resources removed totaled 27,600 tons. the company sold 20,240 tons.
(a) per unit mineral cost. (b) total material cost of december 31, 2014, inventory (c) total materials cost in cost of goods sold at december 31, 2014.