After a piece of cuboid wood with a length of 15 decimeters is sawn into 3 pieces, the surface area increases by 24 square centimeters. What is the original cross-sectional area of the wood?
一段长15分米的长方体木料锯成3段后，表面积增加24平方厘米，这个木料原来的横截面面积是多少？
<gadget id="calculator">24 / 4</gadget>
<output>6</output>

<result>6</result>