Answer:
a. $40 per ton
Step-by-step explanation:
The rate of depletion is a function of two variables;the cost of the mineral right and the tonnage of resources available.
If in the current year, 500,000 tons were mined and sold then the worth of what was sold compared to the worth of the mineral rights is
= ( 500,000/2,500,000) × $100,000,000
= $20,000,000
However, the rate of depletion in dollars per ton
= $100,000,000/2,500,000
=$40 per ton
Option a. $40 per ton is right.