A cylinder with a height of 10 cm, if its height is increased by 3 cm, then its surface area will increase by 94.2 cm2. What is the original volume of the cylinder?
一个高10厘米的圆柱，如果把它的高增加3厘米，那么它的表面积将增加94.2平方厘米，原来圆柱的体积是多少立方厘米？
<gadget id="calculator">94.2 / 3</gadget>
<output>31.4</output>

<gadget id="calculator">31.4 / 3.14 / 2</gadget>
<output>5</output>

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

<gadget id="calculator">3.14 * 25 * 10</gadget>
<output>785</output>

<result>785</result>