A pile of coal is used up (3/5) for the first time, and (3/10) is used up for the second time, leaving 24 tons. How many tons does this pile of coal have?
一堆煤第一次用去它的(3/5)，第二次用去它的(3/10)，还剩24吨，这堆煤原有多少吨？
<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">3 / 10</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">1 - (3/5) - (3/10)</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">24 / (1/10)</gadget>
<output>240</output>

<result>240</result>