A conical container with a height of 18 cm is filled with water, and all the water is poured into a cylindrical container with the same height as the bottom. At this time, how many centimeters is the water surface from the mouth of the cup?
高18厘米的圆锥形容器装满水，把这些水全部倒入与它等底等高的圆柱形容器中，这时水面离杯口多少厘米．
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">18 * (1/3)</gadget>
<output>6</output>

<gadget id="calculator">18 - 6</gadget>
<output>12</output>

<result>12</result>