The distance between A and B is 660 kilometers. A slow train leaves from A and travels 52 kilometers per hour; an express train departs from B and travels 80 kilometers per hour. The two cars drove out at the same time, heading towards each other. How many hours did the two cars meet after departure?
甲乙两地相距660千米，一辆慢车从甲地开出，每小时行使52千米；一辆快车从乙地开出，每小时行驶80千米．两车同时开出，相向而行．两车出发后几小时相遇？
<gadget id="calculator">52 + 80</gadget>
<output>132</output>

<gadget id="calculator">660 / 132</gadget>
<output>5</output>

<result>5</result>