A cube glass tank with a side length of 20 cm is filled with water. Now pour water into an empty glass tank with a length of 20 cm, a width of 16 cm and a depth of 28 cm. How many centimeters is the water from the mouth of the tank? (The thickness of the glass cylinder is ignored)
一个棱长为20厘米的正方体玻璃缸，里面装满水，现在将水倒入一个长20厘米、宽16厘米、深28厘米的空玻璃缸中，水离缸口有多少厘米？(玻璃缸的厚度忽略不计)
<gadget id="calculator">20 / 20 / 16</gadget>
<output>1/16 = around 0.0625</output>

<gadget id="calculator">20 * 20 * (1/16)</gadget>
<output>25</output>

<gadget id="calculator">28 - 25</gadget>
<output>3</output>

<result>3</result>