There is a barrel of oil in the school cafeteria, 40% of which is used, and there are 24 kilograms left. How many kilograms of oil are there in this barrel?
学校食堂有一桶油，用了40%，还剩24千克，这桶油有了多少千克？
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (2/5)</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">24 / (3/5)</gadget>
<output>40</output>

<result>40</result>