A pile of sand, 2/5 of it is used for the first time, and 20% of it is used for the second time, leaving 24 tons. How many tons of this pile of sand are there?
一堆沙子，第一次用去它的(2/5)，第二次用去它的20%，还剩24吨，这堆沙子原有多少吨？
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (2/5) - (1/5)</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">24 / (2/5)</gadget>
<output>60</output>

<result>60</result>