Cut a 5 cm long cylinder of wood into two small cylinders, the surface area increases by 6 cm2, what is the original volume of this wood in cubic centimeters?
把一根长5厘米的圆柱体木料截成2段小圆柱体，表面积增加了6平方厘米，原来这根木料的体积是多少立方厘米．
<gadget id="calculator">6 / 2</gadget>
<output>3</output>

<gadget id="calculator">3 * 5</gadget>
<output>15</output>

<result>15</result>