20% of a barrel of oil is poured out for the first time, and 40 grams more than the first time is poured out for the second time, and there are still 200 grams in the barrel. How many grams of oil is in the barrel?
一桶油第一次倒出20%，第二次比第一次多倒出40克，桶里还有200克，这桶油原来有多少克？
<gadget id="calculator">200 + 40</gadget>
<output>240</output>

<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(1/5) * 2</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (2/5)</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">240 / (3/5)</gadget>
<output>400</output>

<result>400</result>