For a barrel of oil, 40% of the total weight is taken out for the first time, and 3/5 of the remaining weight is taken out for the second time, leaving 36 kilograms of oil in the barrel. How many kilograms of oil is in this barrel.
一桶油，第一次取出总重量的40%，第二次取出余下重量的(3/5)，桶里还剩下36千克油．这只桶里原有油多少千克．
<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">1 - (3/5)</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">40 / 100</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">36 / (2/5) / (3/5)</gadget>
<output>150</output>

<result>150</result>