Depletion Amounts Salty Corporation purchased a salt mine in lower Michigan for $90,000,000. Salty expects to recover 2 million tons of salt from the mine. Because of its location, Salty expects to pay $8,000,000 to refill the mine once production is completed, and has agreed to sell the land to a local community college for $1,600,000. During the first four years of operations, Salty produced 40,000, 120,000, 300,000, and 180,000 tons of salt, respectively. Determine the amount of:

a. Depletion for each of the four years.

b. Accumulated depletion at the end of each of the four years.

c. Book value of the mine at the end of each of the four years based on its initial payment of $90,000,000.