The distance between the two places is 156 kilometers. Cars A and B drive from opposite places at the same time, and the two cars meet after 2 hours. Car A travels 42 kilometers per hour, how many kilometers per hour does Car B travel?
两地相距156千米，甲、乙两车同时从两地相对开出，2小时后两车相遇．甲车每小时行驶42千米，乙车每小时行驶多少千米？
<gadget id="calculator">42 * 2</gadget>
<output>84</output>

<gadget id="calculator">156 - 84</gadget>
<output>72</output>

<gadget id="calculator">72 / 2</gadget>
<output>36</output>

<result>36</result>