Xiaojun's house is 600 meters away from his grandmother's house. One day he took a dog from home to grandma's house. As soon as he set off, the dog ran to grandma's house. When he arrived at grandma's house, he returned immediately. When he came back and met Xiaojun, he ran to grandma's house again. The dog kept running back and forth like this. It is known that Xiaojun walks 50 meters per minute, and the dog runs 200 meters per minute. Ask Xiaojun how many meters did the dog run when he arrived at his grandmother's house?
小军家距外婆家600米，一天他带一条狗，从家去外婆家，一出发狗就跑向外婆家，到了外婆家立即返回，回来遇到小军时，它又跑向外婆家，狗就这样来回不停地跑．已知小军每分钟走50米，狗每分钟跑200米．问小军到外婆家时，狗共跑了多少米路？
<gadget id="calculator">600 / 50</gadget>
<output>12</output>

<gadget id="calculator">200 * 12</gadget>
<output>2_400</output>

<result>2_400</result>