pile of coal was transported away on the first day (1/5), and 3 trucks were added on the second day, resulting in 120 tons more than the first day, and a total of (1/2) of the coal was transported in two days ), how many tons are there in this pile of coal?
一堆煤，第一天运走了(1/5)，第二天增加了3辆货车，结果比第一天多运了120吨，两天一共运走了这堆煤的(1/2)，这堆煤一共有多少吨．
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

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

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

<gadget id="calculator">(1/2) - (2/5)</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">120 / (1/10)</gadget>
<output>1_200</output>

<result>1_200</result>