40% of a barrel of oil is poured out for the first time, and 1/5 is poured out for the second time, leaving 10 kilograms. How many kilograms did the barrel of oil originally weigh?
一桶油，第一次倒出40%，第二次倒出(1/5)，还剩10千克，这桶油原来重多少千克？
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

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

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

<gadget id="calculator">10 / (2/5)</gadget>
<output>25</output>

<result>25</result>