A cylinder, when its height decreases by 3 cm, its surface area decreases by 75.36 cm2. If the height of the cylinder is 12 cm at this time, what is the original volume of the cylinder in cubic centimeters?
一个圆柱，当它的高减少3厘米时，它的表面积减少75.36平方厘米．如果这时圆柱的高是12厘米，原来这个圆柱的体积是多少立方厘米？
<gadget id="calculator">75.36 / 3</gadget>
<output>25.12</output>

<gadget id="calculator">25.12 / 3.14 / 2</gadget>
<output>4</output>

<gadget id="calculator">12 + 3</gadget>
<output>15</output>

<gadget id="calculator">3.14 * 4 * 4 * 15</gadget>
<output>753.6</output>

<result>753.6</result>