The bottom of a cuboid water tank is 40 cm long and 30 cm wide. If 75 liters of water are poured into it, what is the height of the water surface?
长方体水箱的底长40厘米，宽30厘米，如果注入75升水，求水面的高度？
<gadget id="calculator">40 * 30</gadget>
<output>1_200</output>

<gadget id="calculator">1_000 / 1_200</gadget>
<output>5/6 = around 0.833333</output>

<gadget id="calculator">75 * (5/6)</gadget>
<output>125/2 = around 62.5</output>

<result>125/2 = around 62.5</result>