A ship goes back and forth between A and B ports, which are 1200 nautical miles apart. It travels 200 nautical miles per hour when it goes there, and travels 300 nautical miles per hour when it arrives. How many hours does it take to go back and forth?
一艘轮船往返于相距1200海里的甲、乙两港，去时每小时200海里，来时每小时行300海里，来去共花了多少小时？
<gadget id="calculator">200 + 300</gadget>
<output>500</output>

<gadget id="calculator">2 / 500</gadget>
<output>1/250 = around 0.004</output>

<gadget id="calculator">1_200 * (1/250)</gadget>
<output>24/5 = around 4.8</output>

<result>24/5 = around 4.8</result>