cuboid fuel tank has a volume of 21L, measures 40cm long and 21cm wide from the inside, how high is the fuel tank in cm?
一个长方体油箱的容积是21L，从里面量长40cm、宽21cm，这个油箱高多少cm？
<gadget id="calculator">40 * 21</gadget>
<output>840</output>

<gadget id="calculator">1_000 / 840</gadget>
<output>25/21 = around 1.190476</output>

<gadget id="calculator">21 * (25/21)</gadget>
<output>25</output>

<result>25</result>