A rectangular parallelepiped glass container is 3dm in length and width from the inside, pour 5L of water into the container, and then put a stone into the water and submerge it. At this time, the water depth in the container is measured to be 1.5dm. What is the volume of this stone?
一个长方体玻璃容器从里面量长、宽均为3dm，向容器中倒入5L水，再把一块石头放入水中浸没．这时量得容器内的水深1.5dm．这块石头的体积是多少？
<gadget id="calculator">3 * 3 * 1.5</gadget>
<output>13.5</output>

<gadget id="calculator">13.5 - 5</gadget>
<output>8.5</output>

<result>8.5</result>