The cuboid water tank is 10 decimeters long, 8 decimeters wide, and 7 decimeters deep. Water is housed, and a small cuboid with a length of 5 cm and a width of 4 cm is put into it (so that the small cuboid is completely submerged). The water surface rises by 3 cm, and the height of the small cuboid how many centimeters?
长方体水箱长10分米，宽8分米，深7分米，装有水，放入一个长5厘米，宽4厘米的小长方体(使小长方体完全淹没)，水面上升3厘米，小长方体高多少厘米？
<gadget id="calculator">5 * 4</gadget>
<output>20</output>

<gadget id="calculator">3 / 20</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">10 * 10 * 8 * 10 * (3/20)</gadget>
<output>1_200</output>

<result>1_200</result>