Two cars, A and B, drive from places A and B opposite each other and meet each other in 5 hours. At this time, car B is 420 kilometers away from place A. It is known that car B travels an average of 60 kilometers per hour. What is the distance between places A and B? km?
甲、乙两辆汽车从A、B两地相对开出，5小时相遇，这时乙车离A地420千米，已知乙车平均每小时行60千米，A、B两地相距多少千米？
<gadget id="calculator">60 * 5</gadget>
<output>300</output>

<gadget id="calculator">300 + 420</gadget>
<output>720</output>

<result>720</result>