A cuboid pool has a length of 40 cm, a width of 20 cm, a height of 15 cm, and a depth of 12 cm. Put a cylindrical part with a bottom area of 90 square centimeters, the water in the pool overflows by 300 cubic centimeters, how many centimeters is the length of the cylindrical part?
长方体水池长40厘米，宽20厘米，高15厘米，池内水深12厘米．放入一个底面积为90平方厘米的圆柱体零件，池中的水溢出300立方厘米，求圆柱体零件长多少厘米？
<gadget id="calculator">15 - 12</gadget>
<output>3</output>

<gadget id="calculator">40 * 20 * 3</gadget>
<output>2_400</output>

<gadget id="calculator">2_400 + 300</gadget>
<output>2_700</output>

<gadget id="calculator">2_700 / 90</gadget>
<output>30</output>

<result>30</result>