There are three piles of coal, A, B, and C, of which A occupies (2/5). If 20 tons are transported from A to B, the three piles of coal are equal. How much coal does C have?
有甲、乙、丙三堆煤，其中甲占(2/5)，若从甲运20吨到乙，则三堆煤相等，丙原有多少煤？
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">(2/5) - (1/3)</gadget>
<output>1/15 = around 0.066667</output>

<gadget id="calculator">20 / (1/15)</gadget>
<output>300</output>

<gadget id="calculator">300 * (1/3)</gadget>
<output>100</output>

<result>100</result>