Fill a fish tank with a length of 60 cm, a width of 30 cm, and a height of 50 cm with water at a height of 30 cm. What is the volume of water injected?
往一个长60厘米，宽30厘米，高50厘米的鱼缸注30厘米高的水，注入的水体积是多少．
<gadget id="calculator">60 * 30 * 30</gadget>
<output>54_000</output>

<result>54_000</result>