The fee for parking in a parking lot for 1 hour (including 1 hour) is 6.5 yuan. If it exceeds 1 hour, you will have to pay 1.5 yuan more for every 0.5 hours you park. Uncle Zhang's car paid 17 yuan when it left the parking lot. How many hours did Uncle Zhang's car park in the parking lot?
一个停车场停车1小时(含1小时)交费6.5元，如果超过1小时，每多停0.5小时要多交1.5元．张叔叔的车在离开停车场时交了17元，张叔叔的车在停车场停了几小时？
<gadget id="calculator">17 - 6.5</gadget>
<output>10.5</output>

<gadget id="calculator">1.5 + 1.5</gadget>
<output>3</output>

<gadget id="calculator">10.5 / 3</gadget>
<output>3.5</output>

<gadget id="calculator">3.5 + 1</gadget>
<output>4.5</output>

<result>4.5</result>