After the 35 cm long cylinder is cut into two small cylinders, one long and one short, according to the ratio of 3:2, the total surface area increases by 30 square centimeters. Find the volume of the longer cylinder cut off.
把长35厘米的圆柱体按3：2截成了一长一短两个小圆柱体后，表面积总和增加了30平方厘米．求截成的较长一个圆柱的体积．
<gadget id="calculator">30 / 2</gadget>
<output>15</output>

<gadget id="calculator">3 + 2</gadget>
<output>5</output>

<gadget id="calculator">35 / 5</gadget>
<output>7</output>

<gadget id="calculator">7 * 3</gadget>
<output>21</output>

<gadget id="calculator">15 * 21</gadget>
<output>315</output>

<result>315</result>