TeX source:

\begin{aligned} & \text { Depletion charger per ton }=\frac{(\text { USD } 375,000-\text { USD } 75,000)}{1,000,000} \\ =& \text { USD o.30 } \\ & \text { Depletion charge for the year }=\text { USD } 0.30 \times 100,000 \\ =& \text { USD } 30,000 \end{aligned}