A cuboid container, measured from the inside, has a length of 15 cm, a width of 12 cm, and a water depth of 8 cm inside. Put a cuboid iron block. The cross section of the iron block is a square with a side length of 5 cm. The iron block is completely submerged in the water. The water level has risen by 1.5 cm, find the length of the iron block.
一个长方体容器，从里面量，长15厘米，宽12厘米，里面的水深8厘米，放人一个长方体铁块，铁块横截面为边长5厘米的正方形，铁块完全浸没在水中，这时水面上升了1.5厘米，求这个铁块的长度．
<gadget id="calculator">5 * 5</gadget>
<output>25</output>

<gadget id="calculator">1.5 / 25</gadget>
<output>0.06</output>

<gadget id="calculator">15 * 12 * 0.06</gadget>
<output>10.8</output>

<result>10.8</result>