A boy, a girl and a dog are standing together on a long, straight road. Simultaneously, they all start walking in the same direction: The boy at 4 mph, the girl at 3 mph, and the dog trots back and forth between them at 10 mph. Assume all reversals of direction instantaneous.

In one hour, where is the dog and in which direction is he facing?

The dog is 10 miles away facing away from the boy and girl. If they all start out at the same time the dog runs faster than both the boy and the girl so resultantly never reaches either one of them to turn around.

Posted by jduval on 2013-09-24 02:12:27