The distance between the two ports is 680 kilometers. Two ships A and B set off from the two ports at the same time and meet each other in 8.5 hours. It is known that ship A travels 38 kilometers at a time. How many kilometers does the boat travel per hour?
两港相距680千米，甲、乙两船分别从两港同时出发，相对而行8.5小时相遇，已知甲船每小进行38千米．乙船每小时行多少千米？
<gadget id="calculator">680 / 8.5</gadget>
<output>80</output>

<gadget id="calculator">80 - 38</gadget>
<output>42</output>

<result>42</result>