If a cylinder with a height of 5dm is sawed into two pieces, the surface area is increased by 6dm**2, what is the original volume of the cylinder in dm**3.
把一个高5dm的圆柱锯成两段，表面积增加6dm**2，原来圆柱体积是多少dm**3．
<gadget id="calculator">6 / 2</gadget>
<output>3</output>

<gadget id="calculator">2 - 1</gadget>
<output>1</output>

<gadget id="calculator">3 * 1 * 5</gadget>
<output>15</output>

<result>15</result>