4 ms·
Rather crazy online logic test
- brl 18y agoThis kind of reminds me of the 'Mr. P and Mr. S' puzzle. In case you don't know it, there are two numbers (m,n) between 1 and 100. Mr. P is told the product (m * n) and Mr. S is told the sum (m + n), but neither is told the original numbers. Then they have a conversation that goes like this: Mr. P: I don't know what the numbers are. Mr. S: I knew you didn't know them. I don't know them either. Mr. P: Oh, now I know what they are! Mr. S: Me too! I know too!
- johnswamps 18y agoClarification: the range is _exclusive_. Neither number can be 1.
- brl 18y agoAh yes, sorry for not stating the puzzle correctly. That happened when it was explained to me the first time too and I forgot how annoying it is.
- deleted 18y ago[deleted]
- jrp 18y agoDjikstra's reply is pretty cool: http://www.cs.utexas.edu/users/EWD/ewd06xx/EWD666.PDF http://www.cs.utexas.edu/users/EWD/ewd06xx/EWD666.PDF
- rjprins 18y agoI just solved it in 1,5 hour without using pen and paper at all! But then, I didn't prove it was unique and was kind of lucky the solution was small...
- d0mine 18y agoSome variations of the problem: http://www.math.uni-bielefeld.de/~sillke/PUZZLES/logic_sum_product http://www.math.uni-bielefeld.de/~sillke/PUZZLES/logic_sum_p...
- whatusername 18y agowow - I've got the first few easy ones - but that's getting pretty insane.. How long does it take people to finish?
- artlogic 18y agoTook me about an hour or so using only logical reasoning - no guessing.
- gruseom 18y agoWhat a great idea. It may take all my strength to resist getting sucked in, damn you! And I was just telling someone how refreshingly boring Hn has been lately.
- tlrobinson 18y agoSo who's going to write a Prolog program to solve this?
- gambling8nt 18y agoThis is unnecessary; the solution is fairly straightforward, although it would have been more elegant if the problem constrained question 20 better.
- tlrobinson 18y agoYeah, but that's no fun ;)
- unalone 18y agoThis is fascinating! I love that the solution requires balancing every answer with every other answer, so that at time it appears nearly solved but one offset number ruins everything else.
- newt0311 18y agoThe trick is to slowly narrow the choices. After the narrowing, you can start making simplifying assumptions and see if these assumptions are self-consistent with the test. Like a sudoku, but not boring and trivial.
- jyothi 18y agoI just read it out too. Amazing creation as a whole. The toughest thing was i could not scratch out the 'not-possible' options to think more clearly. I took me a little more than an hour.
- newt0311 18y agoThis is fun. When you are done solving it. Try separating the answers into words. You should end up with an interesting sentence.
- bena 18y agoI just read that. Wow. That must have taken a while.
- newt0311 18y ago~30 mins. Its really a game of organization and considering the possibilities. I think the SRAT should replace IQ tests and the SAT. Just have a set of these in increasing levels of difficulty and grade people by which ones they manage to solve.
- rms 18y agoIt's still only testing the ability to perform a particular test. Intelligence is so much broader and is only generally correlated with these types of logic tests.
- bena 18y agoIt's an exercise in inductive reasoning to say the least.
- jcl 18y agoHere's a collection of links about the puzzle, including various methods of solution and other self-referential puzzles (the author's link in the article is broken): http://faculty.uml.edu/jpropp/srat.html http://faculty.uml.edu/jpropp/srat.html