On a map of Yunnan with a scale of 1:6,000,000, the distance between Zhaotong and Kunming is 7 centimeters. Cars A and B leave Zhaotong and Kunming at the same time and drive toward each other. Car A travels 75 kilometers per hour. Car B travels 65 kilometers per hour, after how many hours the two cars meet?
在一幅比例尺为1：6000000的云南地图上量得昭通到昆明的距离为7厘米，甲、乙两车分别从昭通、昆明同时开出，相向而行，甲车每小时行75千米，乙车每小时行65千米，经过几小时两车相遇？
<gadget id="calculator">1 / 6_000_000</gadget>
<output>1/6_000_000 = around 0</output>

<gadget id="calculator">75 + 65</gadget>
<output>140</output>

<gadget id="calculator">7 / (1/6_000_000) / 100_000 / 140</gadget>
<output>3</output>

<result>3</result>