The sum of the volumes of a cylinder and a cone with the same base and height is 60 cubic decimeters. What is the volume of the cone?
等底等高的圆柱和圆锥，它们的体积和是60立方分米，圆锥的体积是多少．
<gadget id="calculator">3 + 1</gadget>
<output>4</output>

<gadget id="calculator">60 / 4</gadget>
<output>15</output>

<result>15</result>