A cuboid with a square bottom is cut off at one end of a cuboid with a height of 2dm, and the remaining surface area is 40dm**2 less than the surface area of the cuboid. What is the volume of the cut cuboid?
一个长方体木块底面是正方形，在它的一端截去一个高是2dm的长方体后，剩下表面积比长方体表面积减少了40dm**2，截去的长方体体积是多少立方分米？
<gadget id="calculator">40 / 4 / 2</gadget>
<output>5</output>

<gadget id="calculator">5 * 5 * 2</gadget>
<output>50</output>

<result>50</result>