A 3-meter-long cuboid is sawn into two equal-length cuboids, and the surface area is increased by 40 square centimeters. What is the original volume of the wood in cubic decimeters?
把一根长3米的长方体木料，锯成两个等长的长方体，表面积增加了40平方厘米，这根木料原来的体积是多少立方分米．
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(2/5) / 2</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">3 * 10</gadget>
<output>30</output>

<gadget id="calculator">(1/5) * 30</gadget>
<output>6</output>

<result>6</result>