Xiaoping and Xiaohong started from school at the same time and walked to Xiaoping's house. Xiaoping walked 20 meters more than Xiaohong every minute. After 30 minutes, Xiaoping arrived home. After arriving home, he immediately returned the same way and met Xiaohong 350 meters away from home. How many kilometers does Xiaohong walk per minute?
小平和小红同时从学校出发步行去小平家，小平每分钟比小红多走20米.30分钟后小平到家，到家后立即原路返回，在离家350米处遇到小红．小红每分钟走多少千米？
<gadget id="calculator">30 * 20</gadget>
<output>600</output>

<gadget id="calculator">600 - 350</gadget>
<output>250</output>

<gadget id="calculator">350 - 250</gadget>
<output>100</output>

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

<gadget id="calculator">250 / 5 / 1_000</gadget>
<output>1/20 = around 0.05</output>

<result>1/20 = around 0.05</result>