ship departs from Port A at 7:30 am at a speed of 30 knots per hour and arrives at Port B at 2:30 pm. How many nautical miles are there between the two ports of A and B?
一艘轮船从上午7时30分以每小时30海里的速度从甲港开出，下午2时30分到达乙港．甲乙两港相距多少海里？
<gadget id="calculator">14.5 - 7.5</gadget>
<output>7</output>

<gadget id="calculator">30 * 7</gadget>
<output>210</output>

<result>210</result>