Cutting a 5-meter-long cylinder of wood into two equal pieces increases the surface area by 12 square meters. What is the volume of this piece of wood in cubic meters?
把一根5米长的圆柱体木料截成相等的两段，表面积增加了12平方米．这根木料的体积是多少立方米．
<gadget id="calculator">12 / 2</gadget>
<output>6</output>

<gadget id="calculator">6 * 5</gadget>
<output>30</output>

<result>30</result>