cylinder and a cone have the same base and height, and the sum of their volumes is 36 cubic decimeters. What is the volume of the cone?
一个圆柱和一个圆锥等底等高，它们体积之和是36立方分米，则圆锥的体积是多少立方分米．
<gadget id="calculator">3 + 1</gadget>
<output>4</output>

<gadget id="calculator">36 / 4</gadget>
<output>9</output>

<result>9</result>