A barrel of oil is used for the first time (1/5), and 20 kg more than the first time is used for the second time, leaving 22 kg. How many kilograms does this barrel of oil weigh?
一桶油第一次用去(1/5)，第二次比第一次多用去20千克，还剩下22千克．原来这桶油有多少千克？
<gadget id="calculator">20 + 22</gadget>
<output>42</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (1/5) - (1/5)</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">42 / (3/5)</gadget>
<output>70</output>

<result>70</result>