Recreational mathematics
Brain teasers
Random logic puzzles and brain teasers. Fun to do and useful for many job interviews!
  1. Liar Truth-teller Brain Teaser
  2. Toggler Brain Teaser
  3. Alien Abduction Brain Teaser
  4. Blue Forehead Room Brain Teaser
  5. Blue Forehead Room Solution
  1. Forehead Numbers Brain Teaser
  2. Light Bulb Switching Brain Teaser
  3. Path Counting Brain Teaser
  4. 3-D Path Counting Brain Teaser