Answer:
a.$8,062,500
Step-by-step explanation:
The amount of depletion is the percentage of the total value that was already mined during the year. The percentage mined during the year is given by:

Since the mineral rights were acquired for $60,000,000, the amount of depletion (D) is given by:

The amount of depletion for the current year is $ 8,062,500