conical measuring cylinder with a radius of 30cm and a height of 10cm is filled with water and poured into a cylindrical container with a bottom diameter of 40cm. What is the height of the water surface at this time?
一个半径为30cm，高为10cm的圆锥形量筒装满水后，倒入一个底面直径是40cm的圆柱形容器中，求这时水面的高度是多少？
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">30 ** 2</gadget>
<output>900</output>

<gadget id="calculator">40 / 2</gadget>
<output>20</output>

<gadget id="calculator">20 ** 2</gadget>
<output>400</output>

<gadget id="calculator">3.14 * 400</gadget>
<output>1_256</output>

<gadget id="calculator">10 / 1_256</gadget>
<output>5/628 = around 0.007962</output>

<gadget id="calculator">(1/3) * 3.14 * 900 * (5/628)</gadget>
<output>7.5</output>

<result>7.5</result>