By Muriel Bristol (Transcriber) | October 16, 2018
Mary’s mum has four children.
The first child is named April.
The second child is named May.
The third child is named June.
What is the name of the fourth child?
[Answer to Puzzle #8 to follow in the next Puzzle]
Solution to Puzzle #7: Double Jeopardy Doors
Double Jeopardy Doors had a certain counter-intuitive aspect that made it more difficult than it would first seem.
Ask each robot in turn, “What the other robot would answer if it were asked which door led to freedom.” If the robot is the liar, it will answer falsely that the truthful robot would direct you to the death door. If the robot is truthful, it will answer truthfully that the liar robot would direct you to the death door.
The counter-intuitive part is that, when you use that particular question, the two robots will agree. Whichever door they both indicate, go through the other one.
Milton Observer 