A cylinder with a height of 5 cm is sawed into two pieces along the diameter of the bottom surface, and its surface area is increased by 40 square centimeters. What is the original volume of the cylinder?
一个高5厘米的圆柱体，沿底面直径将圆柱体锯成两块，其表面积增加40平方厘米，原来这个圆柱体的体积是多少．
<result>62.5</result>