cube water tank with a side length of 30 cm contains 25 cm deep water. Now pour part of the water in the water tank into a rectangular parallelepiped water tank with a length of 40 cm, a width of 40 cm, and a height of 30 cm. The depth of the water is the same, what is the height of the water in the tank at this time?
一个棱长为30厘米的正方体水箱里盛有25厘米深的水，现把水箱中的水倒一部分到长40厘米，宽40厘米，高30厘米的长方体空水箱中，使得两个水箱里的水的深度相同，这时水箱中水的高度是多少？
<gadget id="calculator">30 * 30</gadget>
<output>900</output>

<gadget id="calculator">40 * 40</gadget>
<output>1_600</output>

<gadget id="calculator">900 + 1_600</gadget>
<output>2_500</output>

<gadget id="calculator">25 / 2_500</gadget>
<output>1/100 = around 0.01</output>

<gadget id="calculator">30 * 30 * (1/100)</gadget>
<output>9</output>

<result>9</result>