A pile of coal uses up (1/5), which is exactly (1/2) ton, how many tons does this pile of coal have, and what is the column formula
一堆煤用去(1/5)，正好是(1/2)吨，求这堆煤有多少吨，列式是多少
<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">(1/2) / (1/5)</gadget>
<output>5/2 = around 2.5</output>

<result>5/2 = around 2.5</result>