A 4.9m long bamboo pole is vertically inserted into the pool, the part of the bamboo pole inserted into the bottom mud of the pool is 0.4m, and the exposed part is 0.5m deeper than the pool water. How deep is the pool in meters?
一根4.9m长的竹竿垂直插人水池中，竹竿插人池底泥中部分是0.4m，露出的部分比池水深多0.5m．池水深多少米？
<gadget id="calculator">4.9 - 0.4 - 0.5</gadget>
<output>4</output>

<gadget id="calculator">1 + 1</gadget>
<output>2</output>

<gadget id="calculator">4 / 2</gadget>
<output>2</output>

<result>2</result>