A barrel of oil is used (1/5) for the first time, and 20 kilograms more than the first time is used for the second time, leaving 16 kilograms. How many kilograms is this barrel of oil?
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16千克，这桶油有多少千克？
<gadget id="calculator">16 + 20</gadget>
<output>36</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">36 / (3/5)</gadget>
<output>60</output>

<result>60</result>