The length of a rectangular piece of wood is 30 meters. If it is cut into 3 sections on average, the surface area increases by 20 square meters. Find the volume of the original piece of wood in cubic meters.
一个长方形木料的长是30米，将它平均切成3段，表面积增加了20平方米，求原来这根木料的体积是多少立方米．
<gadget id="calculator">20 / 4</gadget>
<output>5</output>

<gadget id="calculator">5 * 30</gadget>
<output>150</output>

<result>150</result>