A bag of rice, eat it (1/3), exactly 20 kg left. How many kilograms does this bag of rice weigh?
一袋大米，吃去它的(1/3)，正好剩余20千克．这袋大米重多少千克？
<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>