A and B are 1,200 meters apart, and they are walking towards each other. A is 70 meters per minute, and B is 50 meters per minute. A takes a dog and runs back and forth between A and B at 200 meters per minute. When A and B meet, the dog runs How many meters?
甲乙两人相距1200米，两人相向而行，甲每分钟70米，乙每分钟50米，甲带一条狗，来往奔跑于甲乙两人之间，每分钟200米，甲乙相遇时，狗跑了多少米？
<gadget id="calculator">70 + 50</gadget>
<output>120</output>

<gadget id="calculator">1_200 / 120</gadget>
<output>10</output>

<gadget id="calculator">10 * 200</gadget>
<output>2_000</output>

<result>2_000</result>