A cuboid tank with a length of 20 cm, a width of 15 cm, and a height of 16 cm is filled with water. After a stone is placed in it, some water overflows. When the stone is taken out, the water level drops by 4 cm. Find the volume of the stone.
一个长20厘米，宽15厘米，高16厘米的长方体水槽中装满了水，放入一石块浸没后溢出了一些水，再把石块拿出，水位下降了4厘米．求石块的体积．
<gadget id="calculator">20 * 15 * 4</gadget>
<output>1_200</output>

<result>1_200</result>