ship departs from port A at 7:30 am and arrives at port B at 2:30 pm. It is known that the distance between port A and port B is 210 nautical miles. How many nautical miles does the ship travel per hour?
一艘船上午7：30从甲港出发，下午2：30到达乙港，已知甲、乙两港相距210海里，这艘船每小时行多少海里？
<gadget id="calculator">210 / 7</gadget>
<output>30</output>

<result>30</result>