Cutting a 20-decimeter-long cylindrical wood into two identical cylinders, the resulting surface area increases by 18.84 square decimeters. If one of them is screwed into a cone with the largest volume, what is the volume of the cone in cubic decimeters?
把一根长20分米的圆柱形木料，截成2根同样的圆柱体，结果表面积增加18.84平方分米．若把其中的一根旋成体积最大的圆锥体，圆锥体的体积是多少立方分米．
<gadget id="calculator">18.84 / 2</gadget>
<output>9.42</output>

<gadget id="calculator">20 / 2</gadget>
<output>10</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">9.42 * 10 * (1/3)</gadget>
<output>31.4</output>

<result>31.4</result>