Cars A and B drive towards each other from cities A and B respectively for 6 hours at the same time and can meet somewhere on the way. Due to a breakdown on the way, car A was thrown and scanned, and it continued to drive after 2.5 hours of repairs. Therefore, it took 7.5 hours from departure to encounter. So, how many hours did it take for car A to travel from city A to city B?
甲、乙两车分别同时从A、B两城相向行驶6小时后可在途中某处相遇．甲车因途中发生故障抛描，修理2.5小时后才继续行驶．因此，从出发到相遇经过7.5小时．那么，甲车从A城到B城共用了多少小时？
<gadget id="calculator">7.5 - 2.5</gadget>
<output>5</output>

<gadget id="calculator">7.5 + 5</gadget>
<output>12.5</output>

<result>12.5</result>