# The Grey Labyrinth is a collection of puzzles, riddles, mind games, paradoxes and other intellectually challenging diversions. Related topics: puzzle games, logic puzzles, lateral thinking puzzles, philosophy, mind benders, brain teasers, word problems, conundrums, 3d puzzles, spatial reasoning, intelligence tests, mathematical diversions, paradoxes, physics problems, reasoning, math, science.

Message body

 Emoticons View more Emoticons
 [quote="slice of pi"]Here lies the problem with only 5 couples. The professor got 9 different answers. If you pair the couples with letters A&B C&D E&F G&H I&J. Starting with A&B(assuming A&B are the professor and his wife), A..C, D, E, F, G, H, I, J....8 B..C, D, E, F, G, H, I, J....8 C..A, B, E, F, G, H, I....7 D..A, B, E, F, G, H....6 E..A, B, C, D, G....5 F..A, B, C, D....4 G..A, B, C....3 H..A, B....2 I..A....1 J..No hands shaken When you move down the line to J, J shakes 0 hands. Here lies the problem. If you look at the hands shaken by A&B, J has allready shaken 2 hands, and I who supposed to have shaken one hand has shaken 3 hands, and so forth. I have two other possibilities: The word problem says that the professor and his wife invited 4 other couples. It could be possible that they each invited 4 couples making a total of 9 couples. At the end of the evening it said that the professor asked each other person, not, he asked each person. Starting with his wife and then asking every other person (all the ladies to keep it simple) he would get 9 different answers. Then there is a second possible way of looking at this. The Professor and his wife (Hosts) invited 4 other couples (Guests) then you have 9 "Others" for a total of 19 people at the party. The problem says that, "During the evening, various guests and hosts greeted some of the others with handshakes. At the end of the evening, the Professor asked each other person at the party how many different people's hands he/she had shaken; he got nine different answers." But I still don't know how many hands the wife shook! [This message has been edited by slice of pi (edited 06-05-2002 03:11 AM).][/quote]
Options
HTML is OFF
BBCode is ON
Smilies are ON
 Disable BBCode in this post Disable Smilies in this post

 All times are GMT
 Jump to: Select a forum Puzzles and Games----------------Grey Labyrinth PuzzlesVisitor Submitted PuzzlesVisitor GamesMafia Games Miscellaneous----------------Off-TopicVisitor Submitted NewsScience, Art, and CulturePoll Tournaments Administration----------------Grey Labyrinth NewsFeature Requests / Site Problems
 Topic review
Author Message
Posted: Mon Jul 01, 2002 1:32 am    Post subject: 1

Visitor Submitted Puzzles

"The Three Idiots"
Posted: Mon Jul 01, 2002 1:31 am    Post subject: 0

Visitor Submitted Puzzles

"The Three Idiots"
CrystyB
Posted: Sun Jun 30, 2002 1:10 pm    Post subject: -1

Yes, and i got at least a 100 of the puzzles posted on this lovely site.

But i'll let the light side of me take over... OK, you've got 7... 1) Care to tell us how? 2) Have you found any error(s) in the posted solution?
Degenerate
Posted: Sun Jun 30, 2002 5:29 am    Post subject: -2

I still got 7.
Werebear
Posted: Sun Jun 30, 2002 4:36 am    Post subject: -3

ROFL, BearTalon... I loved your post, I'm sure you've seen all mine explaining there is already an answer... I think yours is better. Or at least nicer.

Werebear
CrystyB
Posted: Sat Jun 29, 2002 11:16 am    Post subject: -4

This HAS been solved. Now quit babbling!!!
Degenerate
Posted: Sat Jun 29, 2002 3:56 am    Post subject: -5

I got 7.
Beartalon
Posted: Thu Jun 27, 2002 1:23 am    Post subject: -6

Sometimes I am way too literal and serious for my own good.
Posted: Thu Jun 27, 2002 12:52 am    Post subject: -7

Bear,

I was joking

Beartalon
Posted: Wed Jun 26, 2002 4:44 am    Post subject: -8

It's not that I (we?) don't like alternate answers. It's the fact that the alternate answers in this case are not provable without making some assumption on the meaning in the puzzle. When it comes to word puzzles, meanings are important. Usually the mathematical puzzles like this one depend on logical proofs. In order to have a logical proof, the problem has to be presented in a a logical manner to eliminate all the extraneous possibilities.

Perhaps the question could have been worded better, but if most people interpreted it the same way logically and got the same answer as a result, doesn't that give a lot of credence to the logic of the presentation?

Also, the puzzle was solved visually, by elimination and by deduction. Also, in each case the solution can be extrapolated - if there were 6 couples, the Professor and his wife would each shake five hands given the same criteria. That makes the proof very rigorous and hard to find a good alternative.

------------------
The Bear is Grumpy. Feed Him. Feed Him Now.

[This message has been edited by Beartalon (edited 06-26-2002 12:45 AM).]
Posted: Tue Jun 25, 2002 9:38 pm    Post subject: -9

Hey! You have to include the alternate answer!

Oh well, everyone hates it...
Beartalon
Posted: Tue Jun 25, 2002 3:39 pm    Post subject: -10

4 No way!
Posted: Tue Jun 25, 2002 2:37 pm    Post subject: -11

Care to explain why ?
CrystyB
Posted: Tue Jun 25, 2002 2:35 pm    Post subject: -12

code:
44
44
444
4 44
44 44
4 44
4 44
4 44
4 44
4 44
4 44
44 44
444444444444
44
44
44
44
44

joto25
Posted: Tue Jun 25, 2002 2:03 pm    Post subject: -13

torben bang pedersen
Posted: Tue Jun 25, 2002 10:22 am    Post subject: -14

The professors wike shoke hand with the four invited couples and probably not with the professor. I.e. she must haveshoke hands with eigth persons.

Torben
Posted: Tue Jun 25, 2002 2:17 am    Post subject: -15

Actually the only reason I chose this name is because the knight is my favorite chess piece

Is there such thing as a cool riddle that doesn't have an answer?

Maybe one that has pattern and symmetry involved?

Maybe I shouldn't ask this question. This is the Professor thread after all.
Werebear
Posted: Tue Jun 25, 2002 1:11 am    Post subject: -16

...actually, I really did know the answer. (I couldn't get the first link either) One of the first things you do with a horse is check its mouth before you buy it. The mouth is a good general way to get the health and age of a horse. So if you're buying a horse, look it in the mouth. If a horse is being given to you, you do NOT look it in the mouth - that would be like if you were going to be given a car and you asked if you could take it for a test drive first, and could you get it in a different color, and the passenger side lock is sticky, could they fix that first? *Grin*

Werebear
cha
Posted: Mon Jun 24, 2002 11:32 pm    Post subject: -17

I couldn't get to Groza's first link, and the second one says you can tell how healthy a horse is by looking in its mouth - actually, you can get a pretty good idea about its age.
groza528
Posted: Mon Jun 24, 2002 1:30 pm    Post subject: -18

And another.
Beartalon
Posted: Mon Jun 24, 2002 12:55 pm    Post subject: -19

So why aren't you supposed to look a gift horse in the mouth? Wouldn't that have saved the people who suffered the attack of the Trojan Horse? I'm confused about the origin of that saying.

The other saying coming from the Trojan Horse era was "Beware of Greeks bearing gifts" (which I now say as "Beware of Geeks bearing gifts"). So which one are we suposed to follow?

Too much thinking at 9AM - it's feeding time.

------------------
The Bear is Grumpy. Feed Him. Feed Him Now.
Werebear
Posted: Mon Jun 24, 2002 12:29 pm    Post subject: -20

(looks Gifthorse in the mouth) Why was I always told not to look here?

Werebear
Posted: Sun Jun 23, 2002 4:09 am    Post subject: -21

Finally something worth Looking at that makes plain sense !!!!!!!

Thank new and crystal B

Man I want a new puzzle!!!
groza528
Posted: Sat Jun 22, 2002 4:43 pm    Post subject: -22

Sorry, had to post because that spreadsheet has an odd effect on the post hover
CrystyB
Posted: Fri Jun 21, 2002 3:07 pm    Post subject: -23

Until someone edits that, i'll repost newrone's table:

code:
A	B	C	D	E	F	G	H	I	J	tot
A XX XX 1 O 1 O 1 O 1 O 4
B XX XX 1 O 1 O 1 O 1 O 4
C 1 1 XX XX 1 O 1 O 1 O 5
D O O XX XX 1 O 1 O 1 O 3
E 1 1 1 1 XX XX 1 O 1 O 6
F O O O O XX XX 1 O 1 O 2
G 1 1 1 1 1 1 XX XX 1 O 7
H O O O O O O XX XX 1 O 1
I 1 1 1 1 1 1 1 1 XX XX 8
J O O O O O O O O XX XX 0
tot 4 4 5 3 6 2 7 1 8 0

(i took the liberty to highlight the X's)

[This message has been edited by CrystyB (edited 06-21-2002 11:08 AM).]
Guy Escarfail
Posted: Fri Jun 21, 2002 1:57 pm    Post subject: -24

4 couples : (A1,A2)-(B1,B2)-(C1,C2)-(D1,D2)
Professor : P
Professor's wife : W

A1 : 8 B1 : 7 C1 : 6 D1 : 5 P : 4
A2 : 0 B2 : 1 C2 : 2 D2 : 3 W : 4
newrone
Posted: Thu Jun 20, 2002 10:29 pm    Post subject: -25

A B C D E F G H I J tot
A X X 1 O 1 O 1 O 1 O 4
B X X 1 O 1 O 1 O 1 O 4
C 1 1 X X 1 O 1 O 1 O 5
D O O X X 1 O 1 O 1 O 3
E 1 1 1 1 X X 1 O 1 O 6
F O O O O X X 1 O 1 O 2
G 1 1 1 1 1 1 X X 1 O 7
H O O O O O O X X 1 O 1
I 1 1 1 1 1 1 1 1 X X 8
J O O O O O O O O X X 0
tot 4 4 5 3 6 2 7 1 8 0

... where A&B, C&D, E&F etc are couples, X is invalid (self or husband/wife), 1 is a handshake & O is no handshake. A&B have the same answers, and, yes, they do agree on which hands to shake, whereas I&J don't see eye-to-eye at all... The pattern changes gradually from one end to the other, & is the only solution. Obviously, the Prof & his wife are A&B. Good work, class.

------------------
NEWRONE
CrystyB
Posted: Wed Jun 19, 2002 1:46 pm    Post subject: -26

WB, i don't have the detector handy but i certainly hope that post was soaked in irony...

MacadamiamaN, it is a well known thing in our forums that puzzles (even those solved in the first post! ) in here get updated kind of irregularly (and i say that to be leanient on the administrators). We just have patience until a new idea comes up (interesting puzzles are not common resource, you know?! )...
Posted: Tue Jun 18, 2002 11:15 pm    Post subject: -27

It could very well be 4. However, why hasn't the puzzle been taken out of the unsolved puzzles category??

edited because "" was a smiley face for some reason

[This message has been edited by MacadamiamaN (edited 06-18-2002 07:16 PM).]
Werebear
Posted: Tue Jun 18, 2002 3:17 pm    Post subject: -28

CrystyB - Did anyone tell you the answer to this puzzle is 4?

Werebear
CrystyB
Posted: Tue Jun 18, 2002 2:29 pm    Post subject: -29

This just isn't working... EVERYONE that wants to post ANYTHING about this puzzle (the professor) cannot add anything of value. So i suggest whenever anyone feels like it, they check out other crazy puzzles, like SB or MH or some other i just can't remember.

I'm tired of this puzzle, and since noone is going to give us any new ones, let's ressurect the hottest ones we've already been over!

[This message has been edited by CrystyB (edited 06-18-2002 10:30 AM).]
Posted: Tue Jun 18, 2002 1:48 pm    Post subject: -30

Originally posted by Infinite|Insanity:

aesthetically

I love that word .

------------------
People who think they know everything really annoy those of us that do.
Infinite|Insanity
Posted: Tue Jun 18, 2002 12:34 am    Post subject: -31

Ok, sorry ladies and gents. I hate to post another reply to a thread that has already been beaten to death over and over again with a very large stick on earth, then purgatory for some, then heaven(or hell, whichever you prefer), then some other place that may exist after that. I was very annoyed with the answer until I took out my trusty sword and shield (pencil and pad) and beat my shield with the sword. I set out to prove that any combination between couples is possible other than the 8-0, 7-1, 6-2.........

What I did was arrange everyone in a circle: P, W, AH, AW, BH, BW.........

Then I proceeded to number everyone in any random fashion from 0-8. Then I tried to link everyone up accordingly, starting with the Professor's wife and going clockwise (staying within the rules of the puzzle as stated). Obviously, my random numbering did not work, until I numbered everyone according to the commandments of the majority, which Cadmium so aesthetically provided for us.

Now, I hate to admit that I am now a part of the majority....YUCK!BLEH!PITOOY! Everyone who has doubts still, can try this experiment. If anyone can come up with some other answer to disprove that the couples must be 8-0, 7-1, 6-2 etc. and allow for the Professor and Mary Ann, to be any combination other than the 4-4, you will officially become my deity and I will worship your name.

*disclaimer - 1) you must follow the rules stated in the puzzle. 2) I am not going to worship you.
Beartalon
Posted: Mon Jun 17, 2002 1:24 am    Post subject: -32

<action>
BearTalon hands WereBear a cloth to clean the irony dripping off his keyboard into his lap...
</action>

------------------
The Bear is Grumpy. Feed Him. Feed Him Now.
Werebear
Posted: Sun Jun 16, 2002 12:48 pm    Post subject: -33

Bravo! Bravo! You got the same solution as the rest of us! Bravo!

NEXT!!!

Werebear
Loreweaver
Posted: Sun Jun 16, 2002 7:22 am    Post subject: -34

Of the 9 poeple (other than the professor) at the party, each person shook a different numher of hands. No person could shake more than 8 hands (9 other people, minus their partner). It does not matter how many hands the Professor shook, bcause he did not answer the poll.

We will give each of the 9 people polled a letter from A to I. Since each of the 9 people polled by the professor replied with a different answer, someone (we will call him/her person I) had to have shaken 8 hands, and one person (person A) had to have shaken no hands. 0, 1, 2, 3, 4, 5, 6, 7, 8 were the nine answers given by the persons answering the professor's poll.

The first round of handshakes comes from person I, who shakes 8 hands (everyone but their partner). Person I is partnered with the person who shook no hands (person A). Otherwise, person I would only be able to shake 7 hands (9 other people, minus their partner and the one who did not shake).

We know off the bat that the professor's wife did not shake 8 hands. She could only shake at most 7 hands (9 people, minus the professor and the person who shook 0 hands). We also know she is not the person who shook 0 hands, otherwise person I could not shake more than 7 hands (9 people, minus the professor's wife and their own partner). So, mark the numbers 8 and 0 off your list.

At this point, everyone but person A has shook at least one hand. The 2nd round of shaking comes from a second guest, person H. After this round of shaking, person H has now shaken 7 hands. Person H has shaken with everyone except person A (who shook no hands) and their own partner. The professor's wife cannot be person H, because then everyone but person A would have shaken at least twice (once from person I, and now from the wife), yet we know someone only shook once. So, mark the number 7 from your list.

Everyone except person A and the partner of person H (which we now call person B) have at least shaken twice (once with person I, and now once with person H). Since person A did not shake any hands, that leaves person B as the only one who has shaken hands exactly once. The wife is not person B, because person B is the partner of person H, and we now know person H is a guest. So, mark the number 1 off your list.

The third round of handshaking comes from person G. After the round, person G has shaken 6 hands. They have shaken the hand of person I, person H, and 4 others. They cannot shake with person A (who does not shake any hands), person B (who is done shaking hands), nor their own partner. That leaves only persons C, D, E, F, and the professor. The wife is not person G, otherwise persons C, D, E, and F would have shaken hands at least 3 times (from person I, person H, and the wife), yet we know one of them only shook hands twice. Mark the number 6 off your list.

So far, everyone except persons A, B, and the partner of person G (which we will call person C) has shook at least 3 hands. Person A shook no hands, and B only shook 1 hand, leaving C as the only one who shook exactly 2 hands. Since we know person C is the partner of person G, and that person G is a guest, person C is not the professor's wife. Mark the number 2 off your list.

The next guest, person F, shakes hands. Afterward, person F has shaken 5 hands. These are persons I, H, G, and 2 others. They cannot shake with person A (who shook no hands), person B (who is done shaking), person C (who is also done shaking), nor their own partner. This leaves only persons D, E, and the professor. The wife is not person F, otherwise persons D and E would have shaken hands at least 4 times (with persons I, H, G, and the wife), yet we know one of these people only shook hands 3 times. Mark the number 5 off your list.

At this point, everyone except persons A, B, C, and the partner of person F (which we now call person D) have shaken at least 4 times. Person A shook no hands, person B shook 1 hand, and person C only shook 2 hands. This leaves person D as the only one who has shaken exactly 3 hands so far. The wife cannot be person D, because person D is the partner of person F, and we now know person F is a guest. Mark the number 3 from your list.

At this point, person E has shaken hands with exactly 4 people, persons I, H, G, and F. Person E is the only person who has shook just 4 hands. Since all 8 guests are now accounted for (persons A, B, C, D, F, G, H, and I), the professor's wife must be person E, the only letter not yet assigned. Since person E shook 4 hands, that means the professor's wife shook 4 hands.

P.S. If you map this out on paper, drawing lines between the handshakers, you will notice 2 more things. The professor shook exactly 4 hands, and shook the same 4 hands that his wife shook!
Werebear
Posted: Thu Jun 13, 2002 5:21 pm    Post subject: -35

...of COURSE it is! It's like being mistaken for the President of the Un-- hm. I mean, it's like being mistaken for someone famous, like Michael Jac-- Yecch. I mean, it's like being mistaken for someone really really... oh never mind.

Werebear
Beartalon
Posted: Thu Jun 13, 2002 4:50 pm    Post subject: -36

Cha : you're right. I realized no duplicates was impossible (My own fault for writing far too late at night when my math skills diminish). I haven't tried to solve it properly yet to see if I discern any other pattern.

WereBear : I use that nic on IRC although I haven't been on in a long time (a year or so). There was also another user with that nick but he was from the US and I live in Canada. We both used to haunt the same channel - bearcave.

Thanks for everyone's welcome. Now tell me - is being mistaken for WereBear a blessing?

------------------
The Bear is Grumpy. Feed Him. Feed Him Now.
cha
Posted: Tue Jun 11, 2002 11:50 pm    Post subject: -37

To respond to Beartalon - A is No because if no one can shake hands with on of his or her siblings, that leaves only 12 others available. If one shakes no hands, 13 is the highest number of unique resonses possible.
So, B1 is moot.
B2 would be the person asking could hear a minimum of one number repeated.
C - no real pattern that I could detect. The totals among each set of triplets don't have to add up to the same number...