A cylindrical cup is filled with 15 liters of water, and a cone equal to its base and height is poured into the water. How much water is there in the cup?
一个圆柱体杯子盛满15升水，把一个与它等底等高的圆锥倒放入水，杯子中还有多少水．
<gadget id="calculator">15 / 3</gadget>
<output>5</output>

<gadget id="calculator">5 * 2</gadget>
<output>10</output>

<result>10</result>