Li Shenlin came to school in the morning and walked 70 meters per minute, and arrived at school in 20 minutes. When he came home from school in the afternoon, because it was going to rain, he speeded up and walked 100 meters per minute. How many minutes would it take him to get home from school? (Solve with ratio)
李申林上午来学校每分钟行70米，20分钟就到学校．下午放学回家时由于快下雨了，他加快速度，每分钟行100米，他从学校回到家要多少分钟？(用比例解)
<gadget id="calculator">70 * 20</gadget>
<output>1_400</output>

<gadget id="calculator">1_400 / 100</gadget>
<output>14</output>

<result>14</result>