A passenger car travels 80 kilometers per hour, and a truck travels 60 kilometers per hour. On a map with a scale of 1:3,000,000, the distance between A and B is 28 centimeters. , how many hours later the two cars meet?
客车每小时行80千米，货车每小时行60千米，在比例尺1：3000000的地图上量得A、B两地相距28厘米，客货两车同时从A、B两地出发相向而行，几小时后两车相遇？
<gadget id="calculator">1 / 3_000_000</gadget>
<output>1/3_000_000 = around 0</output>

<gadget id="calculator">80 + 60</gadget>
<output>140</output>

<gadget id="calculator">28 / (1/3_000_000) / 100_000 / 140</gadget>
<output>6</output>

<result>6</result>