For a full barrel of oil, pour out (1/6) of it for the first time, and pour out 20 kilograms more than the first time for the second time. At this time, the ratio of the oil that has been poured out to the remaining oil is 7:5. How many kilograms is this barrel of oil originally?
一满桶油，第一次倒出它的(1/6)，第二次比第一次多倒出20千克，这时已倒出的油与剩下的油的比是7：5．这桶油原来有多少千克？
<gadget id="calculator">7 + 5</gadget>
<output>12</output>

<gadget id="calculator">7 / 12</gadget>
<output>7/12 = around 0.583333</output>

<gadget id="calculator">1 / 6</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">(7/12) - (1/6)</gadget>
<output>5/12 = around 0.416667</output>

<gadget id="calculator">20 / (5/12)</gadget>
<output>48</output>

<result>48</result>