Commuter

Puzzle

A commuter rides the train to and from work each day. Her husband meets her at the train station and drives her home. One day the commuter leaves work early, catches a different train and arrives at the station one hour ahead of schedule. It being a nice day, she decides to walk toward home. Somewhere along the way she meets her husband, driving from home to pick her up at the usual time. She gets in the car and they drive back, arriving 20 minutes earlier than normal. How long was the commuter walking?

Help

Hint

Although it is not necessary to solve the problem, why not assume that the commuter usually arrives at the station at 5pm. Further, assume they usually arrive home at 6pm. How long was she walking then? What if they usually arrive home at 5:30?

Answer

50 minutes

References

Problem Solving by Thomas DeFranco and Charles Vinsonhaler.