John and Fred have a dilemma. They need to get back to town as quickly as possible, but they only have one bicycle between them.

John says, "Here's what we'll do. I'll ride the bike down the road, chain it to a lamp post, and continue on. Then, when you get to the bike, you ride it until you pass me, then go a ways further and chain it to a lamp post, and we'll continue leapfrogging that way until we get to town. Our average speed will be higher and we'll get there sooner."

Fred says, "No, that won't do any good, because even though we alternate walking and riding, every inch of the way will still be traveled on foot by one or the other of us, so we can't get there any faster than if we both walked all the way."

Who is right? Why?

tanstaafl.