A closed cuboid fiberglass is 3 decimeters long, 2.5 decimeters wide, 4 decimeters high, and the water inside is 2 decimeters high. If the fiberglass is placed upright with the right side as the bottom, how many decimeters is the water depth?
一个封闭的长方体玻璃钢，长是3分米，宽是2.5分米，高是4分米，里面水高2分米，如果以右面为底面，把这个玻璃钢竖起来放，水深是多少分米？
<gadget id="calculator">4 * 2.5</gadget>
<output>10</output>

<gadget id="calculator">2 / 10</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">3 * 2.5 * (1/5)</gadget>
<output>1.5</output>

<result>1.5</result>