There is a barrel of oil, 20 kilograms of the total (2/5) is taken out for the first time, and (1/4) of the total is taken out for the second time, and there are 22 kilograms of oil left in the barrel. How many kilograms of oil are there in the barrel?
有一桶油，第一次取出总数的(2/5)还多20千克，第二次取出总数的(1/4)，桶里还剩22千克油，桶内原有多少千克油？
<gadget id="calculator">20 + 22</gadget>
<output>42</output>

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

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(2/5) + (1/4)</gadget>
<output>13/20 = around 0.65</output>

<gadget id="calculator">1 - (13/20)</gadget>
<output>7/20 = around 0.35</output>

<gadget id="calculator">42 / (7/20)</gadget>
<output>120</output>

<result>120</result>