The distance between A and B is 550 kilometers. Two passenger cars depart from A and B at the same time. After 5 hours, the distance between the two cars is still 25 kilometers. It is known that the A passenger car travels 55 kilometers per hour. Find the B train. How many kilometers does the bus travel per hour?
甲、乙两地相距550千米，两列客车同时从甲、乙两地相对开出，5小时后两车还相距25千米，已知甲列客车每小时行55千米，求乙列客车每小时行多少千米？
<gadget id="calculator">550 - 25</gadget>
<output>525</output>

<gadget id="calculator">525 / 5</gadget>
<output>105</output>

<gadget id="calculator">105 - 55</gadget>
<output>50</output>

<result>50</result>