A cylindrical cup is filled with 18 liters of water, and an iron cone with the same height as its bottom is poured into the water, how much water is left in the cup.
一个圆柱体杯中盛满18升水，把一个与它等底等高的铁圆锥倒放入水中，杯中还有多少水．
<gadget id="calculator">18 / 3</gadget>
<output>6</output>

<gadget id="calculator">6 * 2</gadget>
<output>12</output>

<result>12</result>