Everyday a man comes from work and get out the train, at station, at 5 PM. At the same time, everyday, his wife, driving a car, takes him and they go home. One day, the man leaves his work early and get on the sation at 4 PM. So, he decides to go home walking. On the way home, he meets his wife, get in the car and they go home. This day, they arrive at home 10 minutes early. How many time has he walked?