A ship sails from port A to port B at a speed of 40 kilometers per hour. After traveling 20% of the whole journey, it travels for another 1.5 hours. At this time, the ratio of the distance traveled to the distance traveled is 3:1. How many kilometers are there between the two ports of A and B?
一艘轮船以每小时40千米的速度从甲港开往乙港，行了全程的20%后，又行了1.5小时，这时，未行路程与以行路程的比是3：1，甲乙两港相距多少千米？
<gadget id="calculator">1 + 3</gadget>
<output>4</output>

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(1/4) - (1/5)</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">1.5 / (1/20)</gadget>
<output>30</output>

<gadget id="calculator">40 * 30</gadget>
<output>1_200</output>

<result>1_200</result>