The Guardian – Alex Bellos
“Of the many types of puzzle I have posed over the years, the genre that readers seem to respond to best are “common knowledge” logic puzzles. In these problems, there is a situation involving at least two people, each of whom has incomplete information about each other, and the solver makes successive deductions hopping back and forth from each person’s point of view. There is usually a charm to the set-up and even though no technical mathematics is used they are very brain-twisty!” (more)