Donny owns and leases a coal mine to brian. the lease agreement states that brian will pay donny $4 per ton royalty on coal mined. what is brian's percentage depletion deduction for the current year from the information given below? gross income from coal $250,000 income from trucking coal 20,000 royalty paid donny 30,000 taxable income on coal (excluding depletion) 40,000 coal depletion rate 10%