There is a barrel of oil, pour out (1/5) for the first time, pour out 19 kilograms for the second time, and there is still (2/5) of this barrel of oil, how many kilograms is this barrel of oil?
有一桶油，第一次倒出(1/5)，第二次倒出19千克，此时还剩下这桶油的(2/5)，这桶油有多少千克？
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

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

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

<gadget id="calculator">19 / (2/5)</gadget>
<output>95/2 = around 47.5</output>

<result>95/2 = around 47.5</result>