There is a barrel of oil, 30% is taken out for the first time, and (1/5) more kilograms are taken out for the second time than the first time, and there are 3.8 kilograms left in the barrel. How many kilograms does this barrel of oil weigh?
有一桶油，第一次取出30%，第二次取出的比第一次多(1/5)千克，桶里还剩3.8千克，这桶油重多少千克？
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">3.8 + (1/5)</gadget>
<output>4</output>

<gadget id="calculator">30 / 100</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">1 - (3/10) - (3/10)</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">4 / (2/5)</gadget>
<output>10</output>

<result>10</result>