A cone and a cylinder have the same base and height, and their volumes differ by 30 cubic decimeters. What is the volume of the cone?
一个圆锥与一个圆柱等底等高，它们的体积相差30立方分米，这个圆锥的体积是多少立方分米．
<gadget id="calculator">3 - 1</gadget>
<output>2</output>

<gadget id="calculator">30 / 2</gadget>
<output>15</output>

<result>15</result>