In a cuboid oil drum with a length of 30 cm, a width of 30 cm, and a height of 40 cm, the height of the oil is 20 cm. If the oil drum is poured on the ground, how many centimeters is the height of the oil in the drum?
一个长30厘米，宽30厘米，高40厘米的长方体油桶中，油高20厘米，这个油桶倒在地上，这时桶中油高多少厘米？
<gadget id="calculator">30 * 30 * 20</gadget>
<output>18_000</output>

<gadget id="calculator">40 * 30</gadget>
<output>1_200</output>

<gadget id="calculator">18_000 / 1_200</gadget>
<output>15</output>

<result>15</result>