There are three piles of coal, 2.4 tons are transported from the first pile and the second pile to the third pile, and the three piles of coal are exactly equal. It is known that the first pile originally accounted for (2/5) of the total number of piles, how many tons of coal was originally in the third pile?
有三堆煤，从第一堆、第二堆各运2.4吨到第三堆，三堆煤正好相等．已知第一堆原来占总堆数的(2/5)，第三堆原有煤多少吨？
<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">2.4 / (1/15)</gadget>
<output>36</output>

<gadget id="calculator">36 / 3</gadget>
<output>12</output>

<gadget id="calculator">2.4 + 2.4</gadget>
<output>4.8</output>

<gadget id="calculator">12 - 4.8</gadget>
<output>7.2</output>

<result>7.2</result>