There is a barrel of oil, 40% is taken out for the first time, and the amount taken out for the second time is 12 kg less than the first time. At this time, there are 28 kilograms of oil left in the barrel. How many kilograms does the barrel of oil weigh?
有一桶油，第一次取出40%，第二次取出的量比第一次少12千克．这时，桶里还剩油28千克，这桶油重多少千克？
<gadget id="calculator">28 - 12</gadget>
<output>16</output>

<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(2/5) * 2</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">1 - (4/5)</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">16 / (1/5)</gadget>
<output>80</output>

<result>80</result>