cylindrical wood with a length of 3 meters is cut into 4 sections on average, and the surface area increases by 15 square decimeters. What is the volume of this wood in cubic decimeters?
一根长3米的圆柱形木料，平均截成4段后，表面积增加了15平方分米，原来这根木料的体积是多少立方分米．
<gadget id="calculator">15 / 6</gadget>
<output>5/2 = around 2.5</output>

<gadget id="calculator">(5/2) * 3 * 10</gadget>
<output>75</output>

<result>75</result>