A bag of flour, after eating 30kg, there is 20kg left, what percentage of this bag of flour is eaten? what is the correct formula
一袋面粉，吃了30kg后，还剩20kg，吃了这袋面粉的百分之几？正确的算式是多少
<gadget id="calculator">20 + 30</gadget>
<output>50</output>

<gadget id="calculator">30 / 50</gadget>
<output>3/5 = around 0.6</output>

<result>3/5 = around 0.6</result>