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Half Truthful

Logic puzzles require you to think. You will have to be logical in your reasoning.


Puzzle ID:#5160
Fun:*** (2.9)
Difficulty:*** (2.82)
Submitted By:bobbrt*****
Corrected By:Shadows




Three Paley brothers and three Thomson brothers operate a company that manufactures lie detectors. Three of these six men always tell the truth, and three always tell lies; neither set of brothers consists exclusively of liars. Some recent statements from the six men are recorded below. Can you find the six men's full names, and tell which men tell the truth and which tell lies?

1. Alan: "Both my brothers tell lies."
2. Boris: "Both my brothers tell the truth."
3: Chuck: "Alan and Boris are both liars."
4. Dalman: "Chuck and I are brothers."
5. Edwin: "Boris and I are brothers."
6. Finney: "Edwin tells the truth."
7. Finney: "Boris is one of the Paleys."


Alan Thompson, Liar
Boris Paley, liar
Chuck Thomson, truthteller
Dalman Paley, liar
Edwin Paley, truthteller
Finney Thomson, truthteller

Neither set of brothers consists entirely of liars (introduction), so neither consists entirely of truthtellers, either. Boris, then, can't be telling the truth (clue 2); Boris is a liar. If Alan lies, then Chuck tells the truth (clue 3), and vice versa, so between Alan and Chuck, one is a liar and one a truthteller. By elimination, Dalman, Edwin, and Finney are, in some order, one liar and two truthtellers. If Finney is a liar, so is Edwin (clue 6), which is impossible; so Finney tells the truth and so does Edwin (Clue 6); Dalman, then, is a liar. Boris is a Paley (clue 7). Edwin is a Paley (clue 5). Chuck and Dalman are not brothers (clue 4), so one is a Paley and the other a Thomson; by elimination, Alan and Finney are both Thomsons. Finney Thomson tells the truth, so Alan Thomson is a liar (clue 1) and Chuck is a truthteller (clue 3). Boris Paley lied when he said both of his brothers tell the truth (clue 2); one of his brothers is Edwin Paley, a truthteller, so the other must be a liar - and therefore the third Paley can't be Chuck, a truthteller, so must be Dalman, a liar. By elimination, Chuck is a Thompson. it?


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Jul 12, 2002

Fantastic puzzel!
Jul 13, 2002

eegads man, that is truly confusing
Jul 14, 2002

Truly a mind-boggler. good job
Jul 17, 2002

got it after about an hour of taking notes and stuff. my brain hurts :-( wonderful teaser
Jul 17, 2002

extremely confusing but well thought ot good job.
Aug 06, 2002

I enjoyed it.
Aug 06, 2002

eegads!!!!!! LOL!
Aug 06, 2002

I think this one is already on this site under a different name (about 60% sure). It's a good puzzle in any case.
Aug 20, 2002

I thought that I had rated this one b4-like sillywilly's thinking, maybe there's a double.
Aug 20, 2002

boy am I glad I don't get charged by the minute for internet connection. this would have cost me a small fortune. Well done.
Aug 22, 2002

How do you jump to Boris being a "LIAR" with no facts?
Oct 08, 2002

Jul 29, 2003

Broris can only be a liar because if he was truthful, his two brothers would be truthful - making the three other brothers liars - which can't happen as stated in the question. VERY GOOD Teaser! one of my favs cuz it took me a while to solve!!
Jun 25, 2004

This teaser seems a lot like part of the movie "Labyrinth." She encounters two doors, each with two characters, two lie and the other two tell the truth, and she has to figure out which door leads to the castle and which one leads to certain death. Good teaser none-the-less, a logical brain-buster.
Jun 25, 2004

wow really confusing, lots of thinking , it takes quite a while to get it.. great one
Jun 25, 2004

That was one of the best on the site. If it was original, great job.
Jun 27, 2004

wow! that was WAY too confusing for me!! i gave up! i don't like this one, sorry!
Jun 29, 2004

Feb 12, 2005

No I don't get it! I usually enjoy your teasers, but this one bombed!!!
Nov 15, 2005

"neither set of brothers consists exclusively of liars" is redundant. It can be deduced from Alan's statement.
Jan 07, 2009

Hoe can something that at first glance make no sense, then on second thought have possibilities of a solution be fun? This Teaser is difficult, boring and possess no true answer other then-
six brothers have the capacity to lie, and six brothers have the ability to tell the Truth.
Jan 07, 2009

This was challenging, but so fun! I love logic teasers--when I finally solve them, I feel like I really accomplished something. And my brain feels stretched!
Jan 07, 2009

these take time but everything fits if you read the clues carefully, Good job
Jan 07, 2009

If you can unscramble your brain, it becomes fairly easy.
Jan 07, 2009

i dont know what everyone is getting pissy about-- this was cute and actually pretty easy--

well done sweetie
Jan 07, 2009

everything fit together perfectly.. took like 10 mins though.. was a fun way to start a wed morning :-)
Jan 07, 2009

Didn't get it!!!
Jan 07, 2009

I guess it was well thought out, but I got lost right at the start. Thanks anyways, for posting.
Jan 07, 2009

gawd. hard from the start til the end..
Jan 08, 2009

i don't get it at all it hurts my brain
Mar 01, 2009

Took me about 15 minutes but I got it! Good one!
Jan 07, 2012

It would seem that there are some liars out there.... hmmm
Jan 07, 2012

That was awesome! It took a long time, but definitely well worth the effort. Great work.
Jan 07, 2012

It made my brain work hard this morning,but it prevailed.Great mental workout. Hi to a couple of YOUNG ladies on I met on briangle.
Jan 07, 2012

For me the second line gave the first big clue, after that it became easy as long as you didn't become too confused. Loved it.
Jan 07, 2012

I don't care for these logic style. and by the way I think there is a little more deer fly too cute bug then cute bug let's on.
Jan 07, 2012

True, the first to points are the best hints.

Took me 3 hours to solve this, haha
Jan 07, 2012

first two*
Jan 07, 2012

this is a basic logic grid puzzle. if you like this kind of puzzle just google "how to solve a logic grid puzzle." if you draw out the grid, it only takes a minute or two to solve.
Jan 09, 2012

Excellent puzzle. And I'm not lying!
Dec 19, 2012

best liar-truth puzzle of all time.
Jan 08, 2015

This "answer" to this puzzle depends solely on the fact you know Alan and Chuck are brothers at the beginning which you don't figure out till after you know who tells the truth and who is lying. The whole explanation is incorrect to figure out the answer. Below is the following order of events and how you should solve this puzzle, the other way is confusing.

***If you look at all the clues after you determine Boris is a liar none are much help until you get to Finney. If you play with the idea Finney tells the truth then Edwin tells the truth too but no other information is reveled except that Edwin and Boris are brothers with the last name Paley. You know there are two more liars and one more truth teller with no way to identify them.

If you start at the top again and say Alan is a truth teller that would make both Chuck and Dalman liars and brothers which is impossible (Clue 4). So now you know Alan is a liar which makes Chuck a truth teller (Clue 3) and thus makes Dalman the final liar.

Now you come to the issue of last names. Chuck and Dalman are not brothers (Clue 4) and so by elimination Alan and Finney are both Thomsons. Boris Paley lied when he said both of his brothers tell the truth so because Edwin, who is already determined to be his brother tells the truth, Dalman must be the other brother because he is a liar. By elimination, Chuck is a Thompson.***
Jan 28, 2017

I got a different answer. And it seems to work.
Alan Paley - Truth
Edwin Paley - Liar
Finny Paley - Liar

Boris Thompson - Liar
Chuck Thompson - Liar
Dalman Thompson - Truth

Boris we know must be a liar. But Edwin could be a liar. In that case Finny too is a liar. Working the clues from there seems to give a different but correct answer from the one given in the teaser.

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