Two cars, A and B, set off from cities A and B at the same time and drive towards each other. Car A travels 55 kilometers per hour, and car B travels 70 kilometers per hour. When they meet, the distance traveled by car A is less than that of car B. 45 kilometers, how long did it take for the two cars to meet each other?
甲、乙两辆汽车分别同时从A，B两城出发，相向而行，甲车每时行55千米，乙车每时行70千米，相遇时甲车所走的路程比乙车少45千米，两车从出发到相遇一共用了多长时间？
<gadget id="calculator">70 - 55</gadget>
<output>15</output>

<gadget id="calculator">45 / 15</gadget>
<output>3</output>

<result>3</result>