A cuboid with a square base, if its height is shortened by 6 centimeters, the surface area will be reduced by 120 square centimeters, how many cubic centimeters should the volume be reduced?
一个长方体，底面是正方形，如果把它的高截短6厘米，表面积就减少120平方厘米，那么体积应减少多少立方厘米．
<gadget id="calculator">120 / 6</gadget>
<output>20</output>

<gadget id="calculator">20 / 4</gadget>
<output>5</output>

<gadget id="calculator">5 * 5 * 6</gadget>
<output>150</output>

<result>150</result>