Two cars start from the same place at the same time. After driving for 4.5 hours, car A falls behind car B by 13.5 kilometers. It is known that car A travels 35 kilometers per hour. How many kilometers does car B travel per hour?
两辆汽车同时从同地开出，行驶4.5小时后，甲车落在乙车的后面13.5千米，已知甲车每小时行驶35千米，乙车每小时行驶多少千米？
<gadget id="calculator">13.5 / 4.5</gadget>
<output>3</output>

<gadget id="calculator">35 + 3</gadget>
<output>38</output>

<result>38</result>