It is known that if a cuboid is reduced by 15 cm in length and 15 cm in width, it becomes a cube, and the surface area of this cube is 5400 cm2. What is the volume of the original cuboid?
已知：一个长方体如果长减少15厘米，宽增加15厘米，就变成了一个正方体，这个正方体的表面积是5400平方厘米．求原来长方体的体积是多少？
<gadget id="calculator">30 + 15</gadget>
<output>45</output>

<gadget id="calculator">30 - 15</gadget>
<output>15</output>

<gadget id="calculator">45 * 15 * 30</gadget>
<output>20_250</output>

<result>20_250</result>