Two ships, A and B, set off from a dock at the same time in opposite directions. The distance between the two ships is 225 kilometers after sailing for 5 hours. It is known that ship B travels 19.5 kilometers per hour. How many kilometers does ship A travel per hour?
甲、乙两船同时从一个码头向相反方向开出，航行5小时两船相距225千米，已知乙船每小时行19.5千米，甲船每小时行多少千米？
<gadget id="calculator">225 / 5</gadget>
<output>45</output>

<gadget id="calculator">45 - 19.5</gadget>
<output>25.5</output>

<result>25.5</result>