A bag of rice is eaten (4/5) and there are 20 kg left. What is the correct formula for the weight of this bag of rice
一袋大米吃了(4/5)还剩20千克．求这袋大米重量的正确列式是多少
<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">1 - (4/5)</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">20 / (1/5)</gadget>
<output>100</output>

<result>100</result>