A cylindrical piece of wood with a length of 10 decimeters is equally divided into two small cylinders, and the surface area increases by 25.12 decimeters squared. What is the original volume of the cylinder in cubic decimeters?
一根长10分米的圆柱形木头，平均分成两个小圆柱体后，表面积增加了25.12平方分米，原来这个圆柱的体积是多少立方分米．
<gadget id="calculator">25.12 / 2</gadget>
<output>12.56</output>

<gadget id="calculator">12.56 * 10</gadget>
<output>125.6</output>

<result>125.6</result>