The distance between the two cities is 675 kilometers. Two passenger cars A and B respectively depart from the two cities at the same time. After 9 hours of meeting, it is known that car A travels 42 kilometers per hour. How many kilometers does car B travel per hour?
两个城市相距675千米，甲乙两辆客车分别从两个城市同时相对开出，经过9小时相遇，已知甲车每小时行42千米，乙车每小时行多少千米？
<gadget id="calculator">675 / 9</gadget>
<output>75</output>

<gadget id="calculator">75 - 42</gadget>
<output>33</output>

<result>33</result>