A cylinder with a base area of 10 cm2 and a volume of 40 cm3 is twice the volume of a cone of the same height. What is the area of the base of the cone in cm2?
一个圆柱体底面积是10平方厘米，体积是40立方厘米，是和它等高的圆锥体体积的2倍，圆锥体的底面积是多少平方厘米．
<gadget id="calculator">40 / 2</gadget>
<output>20</output>

<gadget id="calculator">40 / 10</gadget>
<output>4</output>

<gadget id="calculator">20 / 4</gadget>
<output>5</output>

<gadget id="calculator">3 * 5</gadget>
<output>15</output>

<result>15</result>