A bag of rice, 1/3 of it is eaten, and there are 20 kilograms left, how many kilograms is the original bag of rice?
一袋大米，吃了它的(1/3)，还剩20千克，这袋大米原有多少千克．
<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">20 / (2/3)</gadget>
<output>30</output>

<result>30</result>