and B go from A to B at the same time. A travels 60 meters per minute, and B travels 90 meters per minute. When B arrives at B, he returns immediately and meets A. When they meet, A still needs to travel for 3 minutes to reach the destination. Arrive at B. What is the distance between A and B?
甲、乙二人同时从A地去B地，甲每分钟行60米，乙每分钟行90米，乙到达B地后立即返回，并与甲相遇，相遇时，甲还需行3分钟才能到达B地．A、B两地相距多少米．
<gadget id="calculator">60 * 3 * 2</gadget>
<output>360</output>

<gadget id="calculator">90 - 60</gadget>
<output>30</output>

<gadget id="calculator">360 / 30</gadget>
<output>12</output>

<gadget id="calculator">12 + 3</gadget>
<output>15</output>

<gadget id="calculator">60 * 15</gadget>
<output>900</output>

<result>900</result>