On a map with a scale of (1/6000000), the distance on the map from City A to City B is 9 cm. There is now a passenger car and a truck departing from the two cities at the same time, and the passenger car travels 100 thousand per hour. m, the speed of the truck is (4/5) that of the passenger car. How many hours did the two cars meet after departure?
在比例尺是(1/6000000)的地图上，量得甲城到乙城的图上距离是9厘米，现有一辆客车和一辆货车同时从甲乙两城相对开出，客车每小时行100千米，货车的速度是客车的(4/5)．两车出发后几小时相遇？
<gadget id="calculator">1 / 6_000_000</gadget>
<output>1/6_000_000 = around 0</output>

<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">100 * (4/5)</gadget>
<output>80</output>

<gadget id="calculator">80 + 100</gadget>
<output>180</output>

<gadget id="calculator">9 / (1/6_000_000) / 100_000 / 180</gadget>
<output>3</output>

<result>3</result>