A 28m long cuboid wood is sawn into 7 sections, the surface area is increased by 120cm**2 compared to the original one, what is the original volume of the wood in cm**3.
把一根长28m的长方体木料锯成7段，表面积比原来增加120cm**2，这根木料原来的体积是多少cm**3．
<gadget id="calculator">120 / 12</gadget>
<output>10</output>

<gadget id="calculator">10 * 28</gadget>
<output>280</output>

<result>280</result>