Monday, 26 August 2013

The Twin Riddle

For anyone who was around  before that might remember my old blog, I had posted the world's toughest riddle.  To my memory, no one ever figured it out though.

Challenge: Solve the riddle and post your answer without any help or research, just good old fashion thinking.

Background...
The way I first heard this riddle was in religious context. They used the extremes of heaven and hell. Being as I am an atheist and don't want to isolate out any non Christians, I often use extremes like paradise and peril to tell the riddle. Sometimes it can be told to suit an individual, like using Las Vegas and Salt Lake City, or saying one way gets you a full body massage from the Swedish bikini team and the other gets you beaten to death with a rusty hammer. The point is that there are two extremes, one great and perfect and the other one horrible and unbearable.

Here goes...
You are forced to follow a road and cannot turn back. You will come to a junction or fork in the road. One of those roads will lead to paradise and the other will lead to peril. You want to take the road to paradise but you can't tell which is which. They look the same. Once you choose a path, you cannot turn around. You are committed to whatever lays ahead. Luckily, there is a gatehouse at the junction. In the gatehouse lives identical twins. They look exactly the same and they know which path is which. The only difference is that one twin always tells the truth and cannot lie. The other twin only lies and cannot tell the truth. The sign on the door tells you to knock and when one of them answers the door, you may ask one question and one question only. Your question will be answered, then you must choose a road and be on your way. You will not be able to tell which twin you are talking to, its impossible to tell them apart. You cannot ask multi part questions or secondary or follow questions. You have one shot...

So what is the question that you ask?

If you ask correctly, you can confidently go on the correct path knowing that you chose with 100% certainty.


Let's hear your question for the Twins.

4 comments:

Ry Elliot said...

I would ask either of them which path would their sister tell me to take. The lying twin would lie and pick the wrong road, and the the truthful twin would honestly tell me which road her sister would pick which would be a lie. So in either case I'd take the opposite road either twin would point out.

Mary-Margret Callahan said...
This comment has been removed by the author.
Mary-Margret Callahan said...

Congratulations Ry Elliot. That is the correct question. Well done. I hope that you didn't cheat. Of course you didn't. Many people have read the riddle. There have been close to 100 hits to date. You were the first to post an answer. That tells me that the rest were either stumped or too afraid to hazard a guess. Good job. I like thinkers.

MMC

Ry Elliot said...

Thank you! No I didn't cheat, it just seemed like the most logical question to ask. I love riddles so I hope you keep them coming.