A man drives from his home at 30 miles per hour to the shopping center which is 30 miles from his home.On the return tri

A man drives from his home at 30 miles per hour to the shopping center which is 30 miles from his home.
某（男）人以30英里/小时的速度从家里开往距离他家30英里的购物中心.
On the return trip he encounters heavy traffic and averages 12 miles per hour.
在回程的路上,他遇到了严重的交通阻塞,所以平均速度是12英里/小时
How much time does the man take in driving to and from the shopping center?
这个（男）人花了多少时间在去购物中心和从那返回家的路上?
计算：
去购物中心--- 30 miles ÷ 30 miles / hour = 1 hour
返程 --- 30 miles ÷ 12 miles / hour = 2.5 hours
(这一步题目没要求需要) 共计 --- 1 hour + 2.5 hours = 3.5 hours