The oil yield rate of a certain type of soybean is 40%. Now it is necessary to extract 40 kg of oil. How many kg of soybeans are needed? (solution by equation)
某种大豆的出油率是40%，现在要榨油40千克，需要大豆多少千克？(用方程解)
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">40 / (2/5)</gadget>
<output>100</output>

<result>100</result>