A cylinder and a cone with the same base and height have a volume difference of 30 cubic meters, what is the volume of the cylinder in cubic meters
等底等高的圆柱和圆锥，体积相差30立方米，圆柱体积是多少立方米
<gadget id="calculator">30 / 2</gadget>
<output>15</output>

<gadget id="calculator">15 * 3</gadget>
<output>45</output>

<result>45</result>