For a bag of rice, 50 kg is poured out for the first time, and the rest (2/5) is poured out for the second time. At this time, the amount of rice poured out is the same as the remaining rice. How many kilograms of rice did this bag have?
一袋大米，第一次倒出50千克，第二次倒出余下的(2/5)，这时倒出的大米和剩下的大米一样多，这袋大米原来多少千克？
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

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

<gadget id="calculator">50 - 20</gadget>
<output>30</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 - (2/5) - (1/2)</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">30 / (1/10)</gadget>
<output>300</output>

<result>300</result>