There is a cuboid tank, measured from the inside, the length is 3dm, the width is 2dm, and the water depth is 1.5dm. A stone is put into the water, and the water depth in the container is measured to be 2.2dm. What is the minimum volume of the stone?
有一个长方体水槽，从里面量，长3dm，宽2dm，水深1.5dm，把一块石头放入水中，这时量得容器中水深2.2dm，这块石头的体积至少是多少？
<gadget id="calculator">2.2 - 1.5</gadget>
<output>0.7</output>

<gadget id="calculator">3 * 2 * 0.7</gadget>
<output>4.2</output>

<result>4.2</result>