Xiaolin and Xiaoqiang are walking toward each other from places A and B which are 22.5km apart. Xiaolin's speed is 2.5km/h, and Xiaoqiang's speed is 3km/h. In order to arrive at the appointed place on time, Xiaolin starts 12 minutes earlier than Xiaoqiang. At the same time, the puppy brought by Xiaolin ran towards Xiaoqiang at a speed of 7.5km/h. When the puppy met Xiaoqiang, he immediately turned back and ran towards Xiaolin until Xiaolin and Xiaoqiang met. Ask for the distance traveled by the puppy?
小林和小强分别从相距22.5km的甲、乙两地相向而行，小林的速度为2.5km/h，小强的速度是3km/h，为了能按时到达约好的地点，小林比小强提前12min开始出发，同时小林所带的小狗以7.5km/h的速度奔向小强，小狗遇到小强后立即回头奔向小林，直到小林、小强相遇，求小狗所走的路程？
<gadget id="calculator">0.2 * 2.5</gadget>
<output>0.5</output>

<gadget id="calculator">22.5 - 0.5</gadget>
<output>22</output>

<gadget id="calculator">2.5 + 3</gadget>
<output>5.5</output>

<gadget id="calculator">22 / 5.5</gadget>
<output>4</output>

<gadget id="calculator">4 * 7.5</gadget>
<output>30</output>

<gadget id="calculator">0.2 * 7.5</gadget>
<output>1.5</output>

<gadget id="calculator">30 + 1.5</gadget>
<output>31.5</output>

<result>31.5</result>