On a map with a scale of 1:6,000,000, the distance from Nanjing to Beijing is 15 centimeters. There are two planes flying opposite each other from Nanjing and Beijing at the same time, each flying 500 kilometers per hour, how many hours later the two planes meet?
在比例尺为1：6000000的地图上量得南京到北京的距离是15厘米．有两架飞机同时从南京和北京相对飞出，每小时各飞行500千米，几小时后两架飞机相遇？
<gadget id="calculator">1 / 6_000_000</gadget>
<output>1/6_000_000 = around 0</output>

<gadget id="calculator">500 + 500</gadget>
<output>1_000</output>

<gadget id="calculator">15 / (1/6_000_000) / 100_000 / 1_000</gadget>
<output>9/10 = around 0.9</output>

<result>9/10 = around 0.9</result>