A pile of coal is used (1/5) for the first time, and the remaining (2/5) is used for the second time, leaving (29/10) tons. How many tons is the pile of coal in total?
一堆煤第一次用去(1/5)，第二次用去剩下的(2/5)，还剩(29/10)吨，这堆煤一共多少吨？
<gadget id="calculator">29 / 10</gadget>
<output>29/10 = around 2.9</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (2/5)</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (1/5)</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">(29/10) / (3/5) / (4/5)</gadget>
<output>145/24 = around 6.041667</output>

<result>145/24 = around 6.041667</result>