One quarter of a pile of coal is removed for the first time, and 120 tons are removed for the second time. At this time, the ratio of the removed tons to the remaining tons is 2:3. How many tons does this pile of coal have? ?
一堆煤第一次运走它的四分之一，第二次运走120吨，这时已远走的吨数和余下的吨数的比是2：3，这堆煤原有多少吨？
<gadget id="calculator">3 + 2</gadget>
<output>5</output>

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

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(2/5) - (1/4)</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">120 / (3/20)</gadget>
<output>800</output>

<result>800</result>