A person is walking along the sidewalk beside the railway. A passenger car comes from behind and takes 15 seconds to pass by. The passenger car is 105 meters long and the speed is 28.8 kilometers per hour. How many kilometers per hour does the pedestrian travel?
某人沿着铁路边的便道步行，一列客车从身后开来，在身旁通过的时间是15秒钟，客车长105米，每小时速度为28.8千米．求步行人每小时行多少千米？
<gadget id="calculator">28.8 - 25.2</gadget>
<output>3.6</output>

<result>3.6</result>