If 40% of a bag of rice is used, the remaining part is 10 kilograms more than the used part, how many kilograms are used.
一袋米，用去40%，剩下的部分比用去的部分多10千克，用去多少千克．
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (2/5) - (2/5)</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">10 / (1/5)</gadget>
<output>50</output>

<gadget id="calculator">50 * (2/5)</gadget>
<output>20</output>

<result>20</result>