There is a barrel of oil, 40% is taken out for the first time, and 10 kg more than the first time is taken out for the second time, leaving 18 kg in the barrel. How many kilograms of oil is in this barrel of oil?
有一桶油，第一次取出40%，第二次比第一次多取10千克，桶里还剩18千克．这桶油原来油多少千克？
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">18 / (1/5)</gadget>
<output>90</output>

<result>90</result>