Problem #PRU-100339

Problems Set theory and logic Mathematical logic

Problem

Tweedledum and Tweedledee travel from their home to the castle of the White Queen. Having only one bicycle among them, they take turns in riding the bike. While one of them is cycling, the other one walks (walking means walking and not running). Nevertheless, they manage to arrive to the castle nearly twice as fast in comparison to if they both were walking all the way to the castle. How did they manage it?