The distance between A and B is 600 kilometers. A passenger car and a truck drive from the two places at the same time. After 2.5 hours, the distance between the two cars is still 400 kilometers. According to this calculation, how many hours will it take for the two cars to meet?
甲乙两地相距600千米，客车和货车分别从两地同时相向开出，2.5小时后，两车还相距400千米，照这样计算，两车再行多少小时才能相遇？
<gadget id="calculator">600 - 400</gadget>
<output>200</output>

<gadget id="calculator">200 / 2.5</gadget>
<output>80</output>

<gadget id="calculator">400 / 80</gadget>
<output>5</output>

<result>5</result>