Xiaohong came home, 30 meters away from the house, her younger sister and the puppy ran towards her together, the speed of Xiaohong and her sister was 50 meters per minute, and the speed of the puppy was 200 meters per minute, after the puppy met Xiaohong Going back and forth between Xiaohong and her sister at the same speed, when Xiaohong and her sister are 10 meters away, how many meters has the puppy run in total?
小红回家，距家门30米，妹妹和小狗一起向她奔来，小红和妹妹的速度都是每分钟50米，小狗的速度是每分钟200米，小狗遇到小红后用相同的速度往返于小红与妹妹之间，当小红与妹妹相距10米时，小狗一共跑了多少米？
<gadget id="calculator">30 - 10</gadget>
<output>20</output>

<gadget id="calculator">50 + 50</gadget>
<output>100</output>

<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(1/5) * 200</gadget>
<output>40</output>

<result>40</result>