A 20 cm long cylinder is cut into 4 cylinders, and the surface area is increased by 20 square centimeters, what is the volume of the cylinder?
一个20厘米长的圆柱截成4个圆柱，表面积增加了20平方厘米，那么这个圆柱的体积是多少．
<gadget id="calculator">20 / 6</gadget>
<output>10/3 = around 3.333333</output>

<gadget id="calculator">(10/3) * 20</gadget>
<output>200/3 = around 66.666667</output>

<result>200/3 = around 66.666667</result>