A square log with a length of 6 meters is sawn into 5 equal sections, and the surface area is increased by 40 square meters compared with the original one. What is the volume of this square log?
一根长6米的方木，锯成相等的5段，表面积比原来增加了40平方米，这根方木的体积是多少？
<gadget id="calculator">4 * 2</gadget>
<output>8</output>

<gadget id="calculator">40 / 8</gadget>
<output>5</output>

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

<result>30</result>