The distance between A and B cities is 2637 kilometers, and two motorcycles drive from opposite sides of the two cities. Car A travels 84 kilometers per hour, and car B travels 90 kilometers per hour. Car B starts after A has traveled 549 kilometers. How many hours will it take for car B to meet A?
甲乙两城相距2637千米，两辆摩托车从两城相对开出．甲车每小时行84千米，乙车每小时行90千米，甲车开出549千米后，乙车才出发，乙车经过多少小时就能和甲车相遇？
<gadget id="calculator">2_637 - 549</gadget>
<output>2_088</output>

<gadget id="calculator">84 + 90</gadget>
<output>174</output>

<gadget id="calculator">2_088 / 174</gadget>
<output>12</output>

<result>12</result>