A cuboid water tank is 30 cm long, 25 cm wide, and 40 cm high when measured from the inside. There is a cube iron block with a side length of 20 cm in the water tank. The water tank is filled with water at first, and then 16400 cubic centimeters of water is released. At this time What is the height of the water level in centimeters?
一个长方体水箱，从里面量长30厘米，宽25厘米，高40厘米，水箱里放有一个边长为20厘米的正方体铁块，水箱起初装满水，后来放出16400立方厘米的水，这时水位的高度是多少厘米？
<gadget id="calculator">30 * 25 * 40</gadget>
<output>30_000</output>

<gadget id="calculator">20 * 20 * 20</gadget>
<output>8_000</output>

<gadget id="calculator">30_000 - 8_000 - 16_400</gadget>
<output>5_600</output>

<gadget id="calculator">30 * 25</gadget>
<output>750</output>

<gadget id="calculator">20 * 20</gadget>
<output>400</output>

<gadget id="calculator">750 - 400</gadget>
<output>350</output>

<gadget id="calculator">5_600 / 350</gadget>
<output>16</output>

<result>16</result>