A pile of coal is burned on the first day (2/5), and 0.8 tons more is burned on the second day than on the first day. At this time, there are still 1.2 tons of unburned coal. How many tons are there in this pile of coal?
一堆煤，第一天烧去(2/5)，第二天比第一天多烧0.8吨，这时还剩下1.2吨未烧，这堆煤共有多少吨？
<gadget id="calculator">0.8 + 1.2</gadget>
<output>2</output>

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

<gadget id="calculator">1 - (2/5) - (2/5)</gadget>
<output>1/5 = around 0.2</output>

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

<result>10</result>