A cuboid glass box is 15 cm long, 12 cm wide, and the height of the water in the box is 4 cm. Now a stone is completely submerged in the water, and the height of the water in the water tank becomes 4.5 cm. What is the volume of the stone?
一个长方体玻璃箱长15厘米，宽12厘米，箱内水的高度是4厘米，现在把一块石头完全浸没在水中，水箱中水的高度变为4.5厘米，求这块石头的体积？
<result>18</result>