Steem Riddle of the Week #3: Doppledanger Robots (Prize for first correct answer)
Riddle #3: Doppledanger Robots
There are 5 robots that appear completely identical, however one of them is good one the other 4 are broken.
You must pick a single robot and ask it two questions. After that you must correctly point to the good robot.
The good robot will answer both questions honestly. The broken robots will all answer one question honestly and lie to one question. You don't know whether they will lie when answering the first question and answer the second honestly, or lie when answering the second question and answer the first truthfully.
What questions should you ask and what is your strategy? Your strategy must guarantee that you always pick the correct robot after asking your two questions in all possible cases.
As usual, the first person to upvote and comment with a valid solution (as decided by me and only me) prior to 12-24-2017 midnight UTC will get the 1 SBD prize! The prize will be sent when this post turns 1 week old.
EDIT: 3 minor clarifications
- All of the robots know which robots are good and which are not.
- You are not limited to yes/no questions. You can ask something like "point to the good robot"
- If you ask a non-yes/no question and the robot lies it may use any lie, but it will never tell the truth. Your strategy must work regardless of what lie it tells.
Don't forget to check out last weeks riddle if you missed it
Last weeks riddle is here : https://steemit.com/life/@droopy/steem-riddle-of-the-week-2-flipping-cards-prize-doubled
Answer to last weeks riddle: https://steemit.com/life/@droopy/steem-riddle-of-the-week-2-flipping-cards-answer-revealed
Can you say "point to the bad robots" ... This is a very interesting challenge.
You could, although an example of lying response to that might be to point to all the robots, or to point to 4 different ones where one is good, so you might not get as much information out of it as like want. Glad you like it :)
Perhaps, but I think I would put it this way.
Ask a question you know to be true.
Is there only one good robot?
if the robot says no you know the next question must be true.
Show me the good robot.
if the robot says yes the next question would be a lie unless it's the good robot.
Which robots are bad?
The robot will point to either one robot
which would make it a liar
or four
which would make it honest
What do you think?
I think you are close, but when asked "which robots are bad" a lying robot could point to 3 bad robots and 1 good robot. He would still be lying in that case because the set of robots that he is pointing to is not the set of bad robots.
There is a more clear solution, but this is close.
Alrighty then.
So a bad robot can tell a partial lie by telling the truth in some cases, say by pointing to 3 bad robots. Can it also lie by omission?
It needs to do what you say, so if you say, "point to 4 bad robots" it would need to point to 4 robots, where at least one of them is not bad.
If you figure out the correct answer it does not involve any complex or confusing lies.
robots [1][2][3][4][5]
ask [3] are you the good robot? yes
what number is the good robot? [3]
[3] is good. both true
ask [3] are you the good robot? yes
what number is the good robot? [4]
[4] is good, 1st was a lie
ask [3] are you the good robot? no
some mysterious question where the lie tells the answer
there is some good thinking in here :)
Congratulations @droopy, this post is the sixth most rewarded post (based on pending payouts) in the last 12 hours written by a Newbie account holder (accounts that hold between 0.01 and 0.1 Mega Vests). The total number of posts by newbie account holders during this period was 3603 and the total pending payments to posts in this category was $1570.22. To see the full list of highest paid posts across all accounts categories, click here.
If you do not wish to receive these messages in future, please reply stop to this comment.
robots [1][2][3][4][5]
...
wait, what happens if I ask robot [3] if the good robot is on its right or left, and [3] is the good robot.. does it then become broken too? IS THIS HOW ALL THE ROBOTS GOT BROKEN?
You can assume that in that case it would say "neither" :)