Two cars, A and B, drive from AB, which is 480 kilometers apart, at the same time. Car A travels 57 kilometers per hour. Car B travels 63 kilometers per hour. How many hours later will the two cars meet?
甲乙两车，从相距480千米的AB两地同时相对开出，甲车每小时行57千米．乙车每小时行63千米，几小时后两车相遇？
<gadget id="calculator">57 + 63</gadget>
<output>120</output>

<gadget id="calculator">480 / 120</gadget>
<output>4</output>

<result>4</result>