In a cuboid glass tank with a length of 6 decimeters, a width of 4 decimeters, and a height of 3 decimeters, the water depth is 2 decimeters. When a rock is completely put into the water, the water level rises by 0.5 decimeters. Find the volume of the rock.
在一个长6分米，宽4分米，高3分米的长方体玻璃缸中，水深2分米，把一个颗岩石完全放入水中后，水面上升了0.5分米，求该岩石的体积．
<gadget id="calculator">6 * 4 * 0.5</gadget>
<output>12</output>

<result>12</result>