The charging standard of a parking lot: 5 yuan for less than 2 hours, 1.5 yuan per hour for more than 2 hours, and 1 hour for less than 1 hour. Uncle Li charged a total of 12.5 yuan for parking once. How many hours did Uncle Li park in this parking lot?
某停车场收费标准：2小时以内收费5元，超过2小时的，每小时收费1.5元，不足1小时的按1小时收费．李叔叔有一次停车共收了12.5元．李叔叔在这个停车场共停车多少小时？
<gadget id="calculator">12.5 - 5</gadget>
<output>7.5</output>

<gadget id="calculator">7.5 / 1.5</gadget>
<output>5</output>

<gadget id="calculator">5 + 2</gadget>
<output>7</output>

<result>7</result>