A person walks at a constant speed along the sidewalk beside the railway, and a passenger car driving at a constant speed comes from behind him and passes the person in 15 seconds. It is known that the bus is 105 meters long and travels 28.8 kilometers per hour. How many kilometers per hour does the pedestrian travel?
某人沿着铁路边的便道匀速步行，一列匀速行驶的客车从他身后开来，用15秒的时间从这人身旁驶过．已知客车长105米，每小时行28.8千米．步行人每小时行多少千米？
<gadget id="calculator">1_000 / 3_600</gadget>
<output>5/18 = around 0.277778</output>

<gadget id="calculator">28.8 * (5/18) * 15</gadget>
<output>120</output>

<gadget id="calculator">120 - 105</gadget>
<output>15</output>

<gadget id="calculator">15 / 15</gadget>
<output>1</output>

<gadget id="calculator">3_600 / 1_000</gadget>
<output>18/5 = around 3.6</output>

<gadget id="calculator">1 * (18/5)</gadget>
<output>18/5 = around 3.6</output>

<result>18/5 = around 3.6</result>