posted by Sahana on .
Every day a commuter takes a train that arrives at her station at precisely 6:00 pm. She is met at the station by her husband, who also arrives at precisely 6:00 pm. He always drives the same route to the station and never varies his speed. One day the commuter takes and earlier train and arrivds at the station at precisely 5:00 pm. She dicides to begin walking home along her husband's usual route. They meet, she gets into the car, and they drive home. They arrive home precisely ten minutes earlier than usual. How long had the commuter been walking?