A bamboo pole with a length of 3.7 meters is vertically inserted into a pool. There is mud at the bottom of the pool. 0.4 meters of the bamboo pole is submerged in the mud, and 0.8 meters is exposed to the water surface. How many meters is the water depth of the pool?
一根长3.7米的竹竿垂直插入水池中，水池底部有淤泥，竹竿有0.4米没入了淤泥中，0.8米露出水面，求水池的水深多少米？
<gadget id="calculator">3.7 - 0.8 - 0.4</gadget>
<output>2.5</output>

<result>2.5</result>