A pile of coal has been transported away (1/3), and there are still 120 tons left. How many tons were there in this pile of coal?
一堆煤，运走了(1/3)，还剩下120吨，这堆煤原来有多少吨？
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 - (1/3)</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">120 / (2/3)</gadget>
<output>180</output>

<result>180</result>