The thickness of two coils of mosquito coils is 0.5 cm. If the diameter of mosquito coils is 18 cm, the width is 0.6 cm. If each coil of mosquito-repellent incense burns 0.3 centimeters per minute, how many minutes can a coil of mosquito-repellent incense burn for?
两盘紧密环绕的蚊香，厚度为0.5厘米，如果蚊香直径为18厘米，宽为0.6厘米．如果每盘蚊香每分钟燃烧0.3厘米，那么一盘蚊香可以燃烧多少分钟？
<gadget id="calculator">18 / 2</gadget>
<output>9</output>

<gadget id="calculator">9 ** 2</gadget>
<output>81</output>

<gadget id="calculator">81 / 0.6</gadget>
<output>135</output>

<gadget id="calculator">3.14 * 135</gadget>
<output>423.9</output>

<gadget id="calculator">423.9 / 0.3 / 2</gadget>
<output>706.5</output>

<result>706.5</result>