A and B move from A to B at the same time, the speed ratio of A and B is 25:21; when A is still (1/7) away from B, B is still 560 meters away from B ． What is the distance between A and B?
甲、乙二人同时从A地走向B地，甲、乙二人的速度之比为25：21，；当甲离B地还有(1/7)时，乙离B地还有560米．A、B两地相距多少米？
<gadget id="calculator">1 / 7</gadget>
<output>1/7 = around 0.142857</output>

<gadget id="calculator">1 - (1/7)</gadget>
<output>6/7 = around 0.857143</output>

<gadget id="calculator">21 / 25</gadget>
<output>21/25 = around 0.84</output>

<gadget id="calculator">(6/7) * (21/25)</gadget>
<output>18/25 = around 0.72</output>

<gadget id="calculator">1 - (18/25)</gadget>
<output>7/25 = around 0.28</output>

<gadget id="calculator">560 / (7/25)</gadget>
<output>2_000</output>

<result>2_000</result>