Xiaoqiang and Xiaoming start from A at the same time and walk in the same direction. Xiaoqiang walks 30 meters per minute, Xiaoming walks 40 meters per minute, and Xiaojun travels from B to A. Xiaojun walks 50 meters per minute. 2.5 minutes after the meeting, Xiaojun and Xiaoqiang meet, how many meters are the distance between A and B?
小强、小明同时从A地出发同向而行，小强每分钟行30米，小明每分钟行40米，同时小军从B地前往A地，小军每分钟行50米，小明、小军两人相遇后2.5分钟，小军小强两人相遇，A、B两地相距多少米．
<gadget id="calculator">50 + 40</gadget>
<output>90</output>

<gadget id="calculator">30 + 50</gadget>
<output>80</output>

<gadget id="calculator">40 - 30</gadget>
<output>10</output>

<gadget id="calculator">2.5 / 10</gadget>
<output>0.25</output>

<gadget id="calculator">80 * 0.25</gadget>
<output>20</output>

<gadget id="calculator">90 * 20</gadget>
<output>1_800</output>

<result>1_800</result>