A train departs from A to B at 5 a.m., travels 120 kilometers per hour as originally planned, and arrives at B at 3 p.m., but the actual arrival time is 5 p.m., which is 2 hours late. How many kilometers does the train actually travel per hour?
一列火车早上5时从甲地开往乙地，按原计划每小时行驶120千米，下午3时到达乙地，但实际到达时间是下午5时整，晚点2小时．问火车实际每小时行驶多少千米？
<gadget id="calculator">15 - 5</gadget>
<output>10</output>

<gadget id="calculator">17 - 5</gadget>
<output>12</output>

<gadget id="calculator">10 / 12</gadget>
<output>5/6 = around 0.833333</output>

<gadget id="calculator">120 * (5/6)</gadget>
<output>100</output>

<result>100</result>