On weekends, Xiaohong walks to the park from home. Two minutes after she set off, the puppy chased her from home with a small ball in its mouth, and caught up with her 200 meters away from home. After giving the ball to Xiaohong, he went home immediately to get the second ball. He caught up with her again 500 meters away from home, and immediately went home to get the third ball after putting down the ball. The puppy just handed the third ball to Xiaohong at the gate of the park. Excuse me, how many minutes does it take Xiaohong to walk from home to the park?
周末，小红从家步行去公园．当她出发2分钟后，小狗从家里含着一个小球去追她，在离家200米的地方追上了她，把球交给小红后立刻回家去取第二个球，在离家500米的地方再次追上了她，放下球后又立刻回家去取第三个球，小狗刚好在公园门口把第三个球交给小红．请问，小红从家步行到公园需要多少分钟？
<gadget id="calculator">7 / 400</gadget>
<output>7/400 = around 0.0175</output>

<gadget id="calculator">1 / (7/400)</gadget>
<output>400/7 = around 57.142857</output>

<gadget id="calculator">1_250 / (400/7)</gadget>
<output>175/8 = around 21.875</output>

<result>175/8 = around 21.875</result>