A cylinder and a cone have the same base and height, and the difference in volume is 20 cubic decimeters. What is the volume of the cone?
一个圆柱和一个圆锥等底等高，体积相差20立方分米，圆锥的体积是多少．
<gadget id="calculator">3 - 1</gadget>
<output>2</output>

<gadget id="calculator">20 / 2</gadget>
<output>10</output>

<result>10</result>