Lucy took 30 minutes to cycle from school to her home at an average speed of 12km/h.
问题描述：
Lucy took 30 minutes to cycle from school to her home at an average speed of 12km/h.
If she wanted to reach home 10 minutes early.what must her average speed be?
答
露西骑车从学校到她家以12km/h的速度平均花30分钟.如果她想提前10分钟到家.她骑车的平均速度是多少呢?
答案 18km/h
0.5x12=6km
6/(1/3)=18km/h