It takes 12 hours for ship A to travel from the east port to the west port, and it takes 8 hours for ship B to travel from the west port to the east port. The two ships set off at the same time. When the time comes, ship A travels 15 kilometers less than ship B. How many kilometers are the distance between the east and west ports?
甲船从东港开往西港要12小时，乙船从西港开往东港要8小时，两船同时出发，遇时甲船比乙船少行了15千米，东西两港相距多少千米？
<gadget id="calculator">2 + 3</gadget>
<output>5</output>

<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(3/5) - (2/5)</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">15 / (1/5)</gadget>
<output>75</output>

<result>75</result>