The sum of the volumes of a cone and a cylinder with the same base and height is 12.56 cubic decimeters. What is the volume of the cone?
等底等高的圆锥和圆柱体积之和是12.56立方分米，圆锥的体积是多少立方分米．
<gadget id="calculator">3 + 1</gadget>
<output>4</output>

<gadget id="calculator">12.56 / 4</gadget>
<output>3.14</output>

<result>3.14</result>