There is a rectangular parallelepiped glass tank with a length of 5dm, a width of 4dm, and a depth of 3dm. Put an irregular iron block into the tank, and then fill it with water (at this time, the water has submerged the iron block). When the iron block is taken out, the water level drops. 0.4dm, what is the volume of this iron block?
有一个长5dm、宽4dm、深3dm的长方体玻璃缸，向缸内放入一块不规则铁块，然后注满水(此时水已淹没铁块)，当取出这个铁块后，水面下降了0.4dm，这个铁块的体积是多少？
<gadget id="calculator">5 * 4 * 0.4</gadget>
<output>8</output>

<result>8</result>