2. 12.35 Four years ago, International Uranium Mines paid $350 million for rights to remove uranium ore (pitchblende) for refining into U3O8 (triuranium octaoxide) for use in nuclear reactor fuels. Of the estimated 6.5 million pounds of ore available, the yearly amounts removed in pounds were 275,000; 250,000; 320,000; and 425,000. Uranium prices per pound over the 4 years were $70, $69, $73, and $75, respectively. For an annual percentage depletion rate of 22%,

(a) what was the total depletion amount over the 4-year period, and

(b) what percentage of the original investment was depleted in the first 4 years?