The oil yield of rapeseed is 42%. An oil mill extracts 2100 kilograms of rapeseed oil, how many kilograms of rapeseed are used?
油菜籽的出油率是42%．一个榨油厂榨出菜籽油2100千克，用油菜籽多少千克？
<gadget id="calculator">42 / 100</gadget>
<output>21/50 = around 0.42</output>

<gadget id="calculator">2_100 / (21/50)</gadget>
<output>5_000</output>

<result>5_000</result>