cylindrical glass with a bottom diameter of 20 cm is filled with water. A conical plumb bob with a bottom diameter of 12 cm and a height of 10 cm is immersed in the water. How many cm does the water level drop after taking out the plumb bob?
一个底面直径为20cm的圆柱形玻璃杯中装有水，水中浸没着一个底面直径是12cm，高是10cm的圆锥形铅锤，取出铅锤后求水面下降了多少cm？
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">12 / 2</gadget>
<output>6</output>

<gadget id="calculator">6 ** 2</gadget>
<output>36</output>

<gadget id="calculator">20 / 2</gadget>
<output>10</output>

<gadget id="calculator">10 ** 2</gadget>
<output>100</output>

<gadget id="calculator">3.14 * 100</gadget>
<output>314</output>

<gadget id="calculator">10 / 314</gadget>
<output>5/157 = around 0.031847</output>

<gadget id="calculator">(1/3) * 3.14 * 36 * (5/157)</gadget>
<output>1.2</output>

<result>1.2</result>