pile of coal, 120 tons more than the total (2/5) was removed, and 20 tons more than (5/6) was removed, how many tons is this pile of coal?
一堆煤，运走的比总数的(2/5)多120吨，剩下的比运走的(5/6)多20吨，这堆煤原有多少吨？
<gadget id="calculator">5 / 6</gadget>
<output>5/6 = around 0.833333</output>

<gadget id="calculator">120 * (5/6)</gadget>
<output>100</output>

<gadget id="calculator">120 + 100 + 20</gadget>
<output>240</output>

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

<gadget id="calculator">(2/5) * (5/6)</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 - (2/5) - (1/3)</gadget>
<output>4/15 = around 0.266667</output>

<gadget id="calculator">240 / (4/15)</gadget>
<output>900</output>

<result>900</result>