Who is lying?
Ann says "Mine watch is showing 7.30." Betty says "Mine and Ann's watches are showing 7.30." Cintia says "Mine or Betty's watches are not showing 7.30." Only one of three friends is lying. Which one could be lying? If you are allowed to chose, which watch will you want to see, to be certain who is lying?
Teacher tip
Use occasionally logic puzzles to exercise students' logical reasoning.
