In a river, two boats are traveling towards each other from the upstream and downstream places A and B respectively, and the velocity of the water is 30 meters per minute. The still water speed of both ships is 700 meters per minute. On this day, the two boats sailed toward each other from A and B respectively, but due to the heavy rain, the water speed was twice the usual, so the meeting point of the two boats was 60 meters away from the usual meeting point. Find the distance between A and B.
在一条河里，两船分别从上、下游的A、B两地相向而行，水的流速是每分钟30米．两船的静水速度都是每分钟700米．这天，两船又分别自A、B两地相向而行，但由于暴雨使水速是平时的2倍，所以两船相遇的地点比平时相遇点相差60米．求A、B两地的距离．
<gadget id="calculator">700 - 30</gadget>
<output>670</output>

<gadget id="calculator">30 * 2</gadget>
<output>60</output>

<gadget id="calculator">700 - 60</gadget>
<output>640</output>

<gadget id="calculator">670 - 640</gadget>
<output>30</output>

<gadget id="calculator">60 / 30</gadget>
<output>2</output>

<gadget id="calculator">700 + 60</gadget>
<output>760</output>

<gadget id="calculator">760 + 640</gadget>
<output>1_400</output>

<gadget id="calculator">2 * 1_400</gadget>
<output>2_800</output>

<result>2_800</result>