If a 5-meter-long log is sawn into 3 sections, the surface area is increased by 120 square centimeters, what is the original volume of the log in cubic centimeters?
把一根5米长的圆木锯成3段，表面积增加120平方厘米，原来这根圆木的体积是多少立方厘米．
<gadget id="calculator">3 - 1</gadget>
<output>2</output>

<gadget id="calculator">2 * 2</gadget>
<output>4</output>

<gadget id="calculator">120 / 4</gadget>
<output>30</output>

<gadget id="calculator">5 * 100</gadget>
<output>500</output>

<gadget id="calculator">30 * 500</gadget>
<output>15_000</output>

<result>15_000</result>