This is a Self-Referential Aptitude Test, developed by James Propp, at UMass-Lowell.
Each question refers to one or more answers on a different question. You should open a separate document to take notes on your process of elimination. Consider not starting the quiz until you have all of the answers.
This thread in the JetPunk subreddit contains a video that outlines my path for solving this puzzle. If you don't want to know all of the answers, and how you might derive them, definitely don't watch it.
Dang you weren’t kidding. This was a challenge. I had to refresh because I took a bit more than an hour, but I solved it without any hints and I’ve never felt prouder to get 100% on a Jetpunk quiz. There are a lot of complex sequences of if/then scenarios required to figure it out. Definitely my favorite quiz on the site and one of my favorite logic puzzles ever, would recommend it to anyone who has a couple hours to spare.
That was great fun, and I was very happy to get them all right! A few wrong turns along the way but fortunately none of them required a complete restart. Thanks @mightythor!
We seem to have lost the ability to color fonts to match the background. I tried style="color: #404858;" and style="color: transparent;", but they aren't working. I am guessing the CSS is overriding it.
I got them all in almost an hour on the nose. Did it with pen and paper and no distractions. I actually clicked two of the wrongs boxes when converting my work from paper to computer (so many Bs and Ds!), but the quiz is solvable for sure. Great fun. General tip is to treat every single thing you see--every question, every answer letter, and every number--as a hint.
This was really clever, especially 6 and 7, which was hilarious! I'm not sure how you made this, this is insanely well done!
I'm a little bitter though since I only missed #11 which threw me off when finding #14/#18/#19. I ended up using deductive reasoning to get them right anyhow, but I only got 19/20... I'm not redoing the quiz for getting a score that's 1 higher, though.
I am really curious at your thought process when creating that type of quizz. Could you please explain briefly how you do it?
Got it right on my second try, figuring out my solution could not work after 30 min on my first attempt must have been one of the most frustrating moments of my life :-)
Inspired from this quiz, I ended up creating a quiz series like this. My technique was to start by setting up questions that can lead you to an answer (in some cases, I don't even have the question decided when I choose the answer). After that, I can use the implications of that answer to lead to another answer, and repeat until I finish. Usually the final answer ends up being something that is useless like "What is this question's answer?"
Because I apparently don't have anything better to do on a Friday night, I put together a full walkthrough! You can view it in Google Docs here. I made it as concise and efficient as I could, but, uh, it's still pretty complicated. I hope it's helpful to anyone who needs it!
I think the logic for #9 on pass three is sus -- "meaning the answer to question 11 couldn't be B". We know it is because we know the answer, but why, at the point, couldn't 11 not being B be valid? Tell me if you disagree.
Question 9 is "The next question with the same answer as this one is question," with option (B) being 11, meaning of course that if the answer is B here then the answer to Question 11 must also be B.
Question 11 is "The number of questions preceding this one with the answer B is," with option (B) being 1.
However, we already know that Question 4's answer is B, so if Question 9 is also B that would mean that there are at least 2 questions prior to 11 with the answer B.
In short: If 9 is B, it leads to a paradox where 11 must be B (because of 9's answer) and can't be B (because it's now incorrect). Thus, the answer to 9 can't be B.
nr 9 indeed can't be B because it would lead to too many B's. But eventhough if 9=B then 11=B and finding out 9 can't be B, that doesnt mean that automatically 11Can't be B. I nearly made that mistake. Eliminated both B's as possible answers for 9 and 11. (Luckily caught it right after I made the error, if you don't know where you made a mistake in this quiz because it was several thought processes and decisions ago, you are in trouble ;))
Simply put, just because 9 can't be B that doesn't mean 11 can't be. (and it actually is ;) )
Oh, of course 11 can still be B at that point! The walkthrough is just saying that if 9 is B, then 11 simultaneously must be and can't be B. That eliminates B as a possible answer for 9, but does not give us any information at all about 11.
The idea is to read the questions and determine what conclusions you can draw about each one. As you are able to draw conclusions on each question, then conclusions about other questions become apparent (this does not necessarily happen in numerical order).
This is where keeping a separate document can be helpful to keep track of your thinking.
If you are lost, there are hints at the top of the comments to help you. If you are still not having fun, there is a video (linked at top of comments) I put together describing how I solved it.
Very clever! I wonder how one creates a quiz like this. Like, how do people come up with these complicated intertwined hints that makes it difficult without being impossible. It took me some time, but I got it all in the end.
I created a quiz series like this. My technique was to set up 2-4 questions that give you enough information for a start. After that, I work off of that. I then try to repeat the process with the answer found imply with other answers.
I think it's more than fair to call this the "HQ on JP". On most quizzes, it's possible to get 100% on the first pass, almost all others on the second pass. There are a small number that require insane rote memorization and then effort for a hour (e.g. the "all subdivisions" variety), and others that require several attempts to ingrain muscle memory (e.g. 100 wpm typing, at least in my case), but no single one requires as many neurons as this one. Well done.
(side note for QM: I wish there was a way to eliminate/DQ the 50 or 60 quizzes where it's obvious that many people cheat -- e.g. an obscure list of 200, where 15% of takers get 100% correct. Just sayin').
You need to consider all the other questions, in particular there's a question asking which is the only odd numbered question where the answer is A. If you've already found a different odd numbered question where the answer is A then it's impossible for question 9 to be A.
If I could read and understand English properly I would have got 20/20 the first time with a touch of assistance, stupid brain seeing proceeding and not preceding but giving up and doing it anyways when I still thought something did not add up.
WOW! So beautiful! I really enjoyed it, thank you!
I think I haven't used info contained in question+answer number 7: I only used it as a check, at the end. Is it possible that there was redundant information? (Just a question, not complaining of course!)
B is incorrect because Question 1 is "the first question with B on its answer" if you select B , then 2nd question's answer is B , but you selected the first B in the 1st question so its wrong.
I did it in sixteen minutes with the aid of an excel spreadsheet. I somehow got number 3 wrong but nothing else and I’m not sure how that works with all the vowel and consonant questions, but I’ll take it!
Edit: Looking at the spreadsheet, I realized I had it right on there and entered it wrong.
I loved this quiz. There's also one thing to mention, but this is a SPOILER, so don't read this if you want to try it for yourself.
Question 12 can also be solved without needing to answer any questions.
If we look at question 8, there are 5 numbered possibilities for the amount of vowel answers in the quiz; 4, 5, 6, 7, 8. Since we know there are 20 questions. We can say that the amount of consonant answers can either be 16, 15, 14, 13 or 12.
We can compare these 5 numbers to the statements in question 12. 16 is only an even number, 15 is an odd number but also divisible by 5, 14 is also only an even number, 13 is an odd number but also a prime number, and finally, 12 is only an even number.
The only option that has been present alone, is A, and since questions can't have multiple answers, it must therefore be A.
All possible choices for Q6 and Q17 lead to logical contradictions. The quiz is flawed with logical paradoxs that can't have a defining answer.
Here's the Logic I have:
First, Try: Q6 = C → "Q17 is E"
Then Q17 = E → "Q6 is all of the above"
That implies Q6 is A, B, C, D, and E → Not possible (can't be multiple in multiple-choice logic)
Second, Try: Q6 = D → "Q17 is none of the above"
Then Q17 = D → "Q6 is none of the above" → So Q6 ≠ A, B, C, or D
(That implies Q6 = E (all of the above))
(But we assumed Q6 = D → Contradiction) So there is a contradiction again.
Third, Try: Q6 = E → "Q17 is all of the above"
Then Q17 = E → "Q6 is A, B, C, D" → Again, multiple values can't all be true (as that leads back to the contradictions we previously tested in Q6 for A, B, C, and D)
Got it with exactly one minute to spare! Well 0:59 to be precise. So good timesetting, great quiz! Was a bigger challenge (timewise) than expected.
I normally don't post my time (this might be the first time, though maybe it did it once or twice on a quiz that was relevant) but wanted to show that the time set for this quiz was well done, also that it I really needed it all, it got tense near the end. (Did not read the comments, did rewrite the questions on a notepad on the computer, might have spend a lot of time typing and removing brackets and spaces... If I knew an answer was wrong I put it in brackets, but also then wanted to remove the spaces. Like B A(C)(E)D and I was fumbling a lot there. Wanted it to not look messy... rows needed to be aligned etc haha recapitalizing, yup was wasting time :D, but it helped visually, a bit..) I rewrote it btw so there was less scrolling and the questions were a bit more comprehensive and concise.
Did it on first try without hint's on and off over the span od 2 days. Looking at the hints now I think a few misunderstandings on my part made it harder than expected.
As an example I only definitely answered n°5 as my 16th question overall (I kept track of the order in which I answered in case I needed to backtrack). I was down to 2 possible answers early on but I don't see how you could answer it without knowing more about the first 4 questions.
If you're not cautious and check the "obvious" answer for 5 imediately you could argue you can do the same with 9 which would lead you in the wrong direction.
In conclusion awesome quizz but I'm glad I didn't look at the hints
I also don't understand the logic behind being able to answer Question 5 at the start of the quiz.
When we start, due to question 1 we can tell that the answer to 1 cannot be A or B, and the answer to 2 cannot be B.
There are then 3 options for question 5. If the answer to 3 is C, then the answer to 5 can be C. If the answer to 4 is D, then the answer to 5 can be D. And of course the answer to 5 can be E.
How can we conclude that the answer to 5 must be E without first eliminating Q3 C and Q4 D as possibilities?
No matter what answer you pick for question 5, the answer will always be the same as the answer for question 5. A question only has one answer, so the answer has to be 5) E.
18/20 - only missed 9 and 19. i'm stuck trying to see why swapping those two answers breaks the logic - is this an alternate solution or is there something I'm missing?
This comment contains hints. Select to see them (not sure about mobile).
These are not comprehensive.
#5 and #20 can each be answered without looking at any other question
Looking at #10 and #16 will give you the answers to both.
Looking at #6 and #17 will allow you to eliminate answers from each. #2 will clarify them.
Reading #7 will eliminate answers from #8. I am not saying you will be able to answer #7.
Use #3, #4 and #8, together.
Those will also help you answer #12, #15, and #13.
Knowing #13, allows you to eliminate answers from several questions.
#2 is your friend. Consider its implications to will help you eliminate answers on many questions .
You know how many questions are on the quiz, and which ones are vowels or consonants.
I probably will put together a comprehensive solution and post it on reddit.
Only took it just now, didn't realize how fun of a 40 minutes that would be.
I got 19/20 cause I apparently can't count, but it was amazing, nonetheless!
I'm a little bitter though since I only missed #11 which threw me off when finding #14/#18/#19. I ended up using deductive reasoning to get them right anyhow, but I only got 19/20... I'm not redoing the quiz for getting a score that's 1 higher, though.
Very well done, but I can't nominate it ;)
https://www.jetpunk.com/user-quizzes/1306568/the-impossible-logic-quiz
Got it right on my second try, figuring out my solution could not work after 30 min on my first attempt must have been one of the most frustrating moments of my life :-)
"This is a Self-Referential Aptitude Test, developed by James Propp, at UMass-Lowell."
I don't believe the source describes his process, but I wonder if an internet search might uncover it.
I dig it.
I think the logic for #9 on pass three is sus -- "meaning the answer to question 11 couldn't be B". We know it is because we know the answer, but why, at the point, couldn't 11 not being B be valid? Tell me if you disagree.
Question 9 is "The next question with the same answer as this one is question," with option (B) being 11, meaning of course that if the answer is B here then the answer to Question 11 must also be B.
Question 11 is "The number of questions preceding this one with the answer B is," with option (B) being 1.
However, we already know that Question 4's answer is B, so if Question 9 is also B that would mean that there are at least 2 questions prior to 11 with the answer B.
In short: If 9 is B, it leads to a paradox where 11 must be B (because of 9's answer) and can't be B (because it's now incorrect). Thus, the answer to 9 can't be B.
Simply put, just because 9 can't be B that doesn't mean 11 can't be. (and it actually is ;) )
The idea is to read the questions and determine what conclusions you can draw about each one. As you are able to draw conclusions on each question, then conclusions about other questions become apparent (this does not necessarily happen in numerical order).
This is where keeping a separate document can be helpful to keep track of your thinking.
If you are lost, there are hints at the top of the comments to help you. If you are still not having fun, there is a video (linked at top of comments) I put together describing how I solved it.
(side note for QM: I wish there was a way to eliminate/DQ the 50 or 60 quizzes where it's obvious that many people cheat -- e.g. an obscure list of 200, where 15% of takers get 100% correct. Just sayin').
Really tricky quiz, I like the concept
I think I haven't used info contained in question+answer number 7: I only used it as a check, at the end. Is it possible that there was redundant information? (Just a question, not complaining of course!)
Guess I'll have to learn some more English before taking such a quiz again haha
finishing the quiz without outside help really feels good and satisfying, i love this quiz
5, 10, 16 and 20 are all easy, the rest? you're in for a long ride...
Edit: Looking at the spreadsheet, I realized I had it right on there and entered it wrong.
Question 12 can also be solved without needing to answer any questions.
If we look at question 8, there are 5 numbered possibilities for the amount of vowel answers in the quiz; 4, 5, 6, 7, 8. Since we know there are 20 questions. We can say that the amount of consonant answers can either be 16, 15, 14, 13 or 12.
We can compare these 5 numbers to the statements in question 12. 16 is only an even number, 15 is an odd number but also divisible by 5, 14 is also only an even number, 13 is an odd number but also a prime number, and finally, 12 is only an even number.
The only option that has been present alone, is A, and since questions can't have multiple answers, it must therefore be A.
and then i got one point
for questions 6 and 17.
how can the answer to 6 be B since it means the answer to 17 is D= the answer to 6 is none of the above
isn’t B one of the above????
or does that not mean what i think it does ?
Here's the Logic I have:
First, Try: Q6 = C → "Q17 is E"
Then Q17 = E → "Q6 is all of the above"
That implies Q6 is A, B, C, D, and E → Not possible (can't be multiple in multiple-choice logic)
Second, Try: Q6 = D → "Q17 is none of the above"
Then Q17 = D → "Q6 is none of the above" → So Q6 ≠ A, B, C, or D
(That implies Q6 = E (all of the above))
(But we assumed Q6 = D → Contradiction) So there is a contradiction again.
Third, Try: Q6 = E → "Q17 is all of the above"
Then Q17 = E → "Q6 is A, B, C, D" → Again, multiple values can't all be true (as that leads back to the contradictions we previously tested in Q6 for A, B, C, and D)
If Q:17 is answer B --> Then Q6 is answer D (according to Q17)
Q6, answer D says "non of the above", where the above are C, D, and E. (B is neither C, nor D, nor E)
So everything works. Q6 answer D tells you the answer to Q17 is not C, D, or E; which is correct if the answer to Q17 is D.
I normally don't post my time (this might be the first time, though maybe it did it once or twice on a quiz that was relevant) but wanted to show that the time set for this quiz was well done, also that it I really needed it all, it got tense near the end. (Did not read the comments, did rewrite the questions on a notepad on the computer, might have spend a lot of time typing and removing brackets and spaces... If I knew an answer was wrong I put it in brackets, but also then wanted to remove the spaces. Like B A(C)(E)D and I was fumbling a lot there. Wanted it to not look messy... rows needed to be aligned etc haha recapitalizing, yup was wasting time :D, but it helped visually, a bit..) I rewrote it btw so there was less scrolling and the questions were a bit more comprehensive and concise.
That's crazy
As an example I only definitely answered n°5 as my 16th question overall (I kept track of the order in which I answered in case I needed to backtrack). I was down to 2 possible answers early on but I don't see how you could answer it without knowing more about the first 4 questions.
If you're not cautious and check the "obvious" answer for 5 imediately you could argue you can do the same with 9 which would lead you in the wrong direction.
In conclusion awesome quizz but I'm glad I didn't look at the hints
When we start, due to question 1 we can tell that the answer to 1 cannot be A or B, and the answer to 2 cannot be B.
There are then 3 options for question 5. If the answer to 3 is C, then the answer to 5 can be C. If the answer to 4 is D, then the answer to 5 can be D. And of course the answer to 5 can be E.
How can we conclude that the answer to 5 must be E without first eliminating Q3 C and Q4 D as possibilities?
hold on im buffering