A cylindrical container filled with water has a bottom radius of 5 cm, a depth of 20 cm, and a depth of 15 cm. Now put a cylinder with a base radius of 2 cm and a height of 1.8 cm vertically into the container, how many centimeters is the water depth at this time?
一个盛有水的圆柱体形容器，底面内半径为5厘米，深20厘米，水深15厘米．现将一个底面半径为2厘米，高为1.8厘米的圆柱体垂直放入容器中，求这时的水深是多少厘米？
<gadget id="calculator">2 ** 2</gadget>
<output>4</output>

<gadget id="calculator">5 ** 2</gadget>
<output>25</output>

<gadget id="calculator">3.14 * 25</gadget>
<output>78.5</output>

<gadget id="calculator">1.8 / 78.5</gadget>
<output>0.02293</output>

<gadget id="calculator">3.14 * 4 * 0.02293</gadget>
<output>0.288001</output>

<gadget id="calculator">0.288001 + 15</gadget>
<output>15.288001</output>

<result>15.288001</result>