Originally posted by Coconut
I think this is right, right?
The wife usually leaves at some specific time, travels to the station in time t(normal), picks up the husband, and travels home in the same amount of time t(normal).
Yesterday, the wife left at the same specific time but met her husband on the road having traveled only time t(early), and drove home in the same amount of time t(early). When they arrived home, it was 10 minutes earlier than usual.
So, we have:
2*t(normal) - 2*t(early) = 10 minutes
t(normal) - t(early) = 5 minutes
Since we also know that when the wife drives for time t(normal) she arrives at the station at 6:00pm, she must have picked up her husband 5 minutes early at 5:55pm. Since the husband left the station at 5:00pm, he must have been walking for 55 minutes.