rectangular parallelepiped container is 15 cm long, 12 cm wide, and 18 cm high when measured from the inside, and it is filled with water. If all the water is poured into a rectangular container with a side length of 20 cm, what is the height of the water surface in cm?
一个长方体容器从里面量长是15厘米，宽是12厘米，高是18厘米，里面装满水，如果把这些水全部倒入一个棱长是20厘米的正方体容器中，水面高是多少厘米？
<gadget id="calculator">20 * 20</gadget>
<output>400</output>

<gadget id="calculator">18 / 400</gadget>
<output>9/200 = around 0.045</output>

<gadget id="calculator">15 * 12 * (9/200)</gadget>
<output>81/10 = around 8.1</output>

<result>81/10 = around 8.1</result>