Xiaoyue and Dongdong start from two places 720 meters apart and travel in the same direction, and Dongdong starts 2 minutes earlier than Xiaoyue. It is known that Xiaoyue's speed is 60 meters per minute, and Dongdong's speed is 50 meters per minute. Meters, let me ask: when Xiaoyue catches up with Dongdong, how many meters has Dongdong walked?
小悦和冬冬分别从相距720米的两地出发同向而行，且冬冬比小悦先出发2分钟，已知小悦的速度是每分钟60米，冬冬的速度为每分钟50米，试问：当小悦追上冬冬的时候，冬冬已经走了多少米？
<gadget id="calculator">50 * 2</gadget>
<output>100</output>

<gadget id="calculator">720 + 100</gadget>
<output>820</output>

<gadget id="calculator">60 - 50</gadget>
<output>10</output>

<gadget id="calculator">820 / 10</gadget>
<output>82</output>

<gadget id="calculator">82 + 2</gadget>
<output>84</output>

<gadget id="calculator">84 * 50</gadget>
<output>4_200</output>

<result>4_200</result>