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## #26 2012-09-06 23:41:34

pRo9aMeR
Member
Registered: 2012-07-28
Posts: 44

### Re: Who has the purple door?

I've edited the puzzle a few more times to make it harder but I think the clue "the 16-student class has an orange door" needs to have "and is next to the exit" put back in.  Am I wrong?  Or have I just done this puzzle too many times and am going crazy?

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## #27 2012-12-08 18:38:18

pRo9aMeR
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Registered: 2012-07-28
Posts: 44

### Re: Who has the purple door?

MIF, I guess that this puzzle is in it's final version for the time being.  Would mind putting it on the website?  I want to know if someone other than phronister (gj again btw!) can solve it!

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## #28 2013-02-04 21:36:07

pRo9aMeR
Member
Registered: 2012-07-28
Posts: 44

### Re: Who has the purple door?

This should be the end-all version of this puzzle!  Whew!

1) Jerek's classroom is the last one on the right.
2) David's class starts at 5:45pm and ends at 8:30pm.
3) Jennifer's Chinese class has a white door.
4) Jessica's class is 2 hours and 15 minutes long and is next to Mr. Nest's class.
5) Joe's class is next to the Music class and the exit.
6) Matthew's class ends at 8pm.
7) Max teaches Literature and is next to Ryan's classroom.
8) Michaela's class is next to Mrs. Smith's class.
9) Mr. Adams' 19-student class is next to Mr. Bush's 27-student class.
10) Mr. Bentley teaches Medicine.
11) Mr. Johnson's class has a blue door and ends at 9:30pm.
12) Mrs. Franklin's class lasts for 3 hours.
13) Michelle's class ends at 9:45pm.
14) Mrs. Jackson's class is between Mr. Bentley's and Mr. Jones' and across from Mrs. Franklin's.
15) Mrs. Wyatt's classroom is next to the class with 30 students.
16) Ryan's class has 38 students and a red door.
17) The 16-student class has an orange door and is not next to a class that ends on the hour.
18) The 22-student class is in between the 30-student class and the 18-student class.
19) The 34-student class has a pink door.
20) The black and grey doors are next to each other and the black-door class starts at 5pm.
21) The class between Jerek's and the red door starts at 7pm.
22) The class that ends at 10pm is in between the red door and the Reading class.
23) The class that ends at 8:45pm is across from Mr. Bush's.
24) The first class on the left has 30 students.
25) The Grammar class is next to Mr. Jones' class.
26) The green door is across from the class that starts at 5pm.
27) The History class is next to the class that starts at 6:15pm.
28) The Listening class starts at 6:45pm.
29) The Medicine class starts at 6pm and has 38 students.
30) The Music class ends 1 hour and 45 minutes before the Chinese class ends.
31) The Speaking class ends when the Literature class begins.
32) The Speaking class starts an hour before the History class starts.
33) The Reading and Writing classes are next to the entrance.
34) The yellow door is across from the class that starts at 7:45pm.
35) There are a total of 255 students and the left side has 5 more students than the right side.
36) Two of the four three-hour-long classes have female teachers.
37) All of the classes are longer than 2 hours and have more than 10 students.

Should I update the OP or just leave it here?

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## #29 2013-02-05 19:51:51

pRo9aMeR
Member
Registered: 2012-07-28
Posts: 44

### Re: Who has the purple door?

I updated the OP with the above post's info.  Should be ready for a spin Phronister!

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## #30 2013-02-09 04:30:34

phrontister
Real Member
From: The Land of Tomorrow
Registered: 2009-07-12
Posts: 4,435

### Re: Who has the purple door?

Hi pRo9aMeR,

Solved! (I think)

I think you can omit clue #37 (see the revised set of clues below):-
1. Re the student numbers I changed clues 9, 15, 18 & 24. That also results in different student numbers for the two unknowns.
2. I'm not sure that you need to state that the classes are longer than 2 hours. I made a note to myself while I was solving the puzzle that the end time for clue #11 might need to change to 10:15pm, but now I don't recall why that was. I'd have to solve the puzzle again to determine the reason.

EDIT 1: I made a further change to the number of students in clues 9 & 18.
EDIT 2: I solved the puzzle using the latest student-number revisions as above, and didn't need clue #37.

Last edited by phrontister (2013-02-09 22:33:42)

"The good news about computers is that they do what you tell them to do. The bad news is that they do what you tell them to do." - Ted Nelson

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## #31 2013-02-09 22:39:20

phrontister
Real Member
From: The Land of Tomorrow
Registered: 2009-07-12
Posts: 4,435

### Re: Who has the purple door?

Hi pRo9aMeR,

Just thought I'd let you know that I've edited my previous post (twice), in case you're subscribed to this thread and I can catch you before you check out my clue revisions.

"The good news about computers is that they do what you tell them to do. The bad news is that they do what you tell them to do." - Ted Nelson

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## #32 2013-02-10 09:40:51

phrontister
Real Member
From: The Land of Tomorrow
Registered: 2009-07-12
Posts: 4,435

### Re: Who has the purple door?

Hi pRo9aMeR,

The fact that not all of the puzzle's components need to be solved to answer the title questions has been bugging us, but I think I may have come up with a couple of new title questions that tightens that up somewhat.

They are:

What is the colour of David's door? At what time does the Speaking class finish?

Unless I've overlooked something, that improves it a fair bit with the solution method I use, but I wonder if it works for your method too.

Last edited by phrontister (2013-02-10 13:14:51)

"The good news about computers is that they do what you tell them to do. The bad news is that they do what you tell them to do." - Ted Nelson

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## #33 2013-02-11 04:19:23

phrontister
Real Member
From: The Land of Tomorrow
Registered: 2009-07-12
Posts: 4,435

### Re: Who has the purple door?

Hi pRo9aMeR,

About two thirds of the way into the puzzle I've found a roadblock that I can't get through without a fair amount of T&E, which is probably not what you're after with this Einstein-type logic puzzle. I recall now that I used T&E there before, but didn't worry about it.

Maybe there's a way through that I'm missing (and maybe your solution method copes with that and mine doesn't), but I've tried and tried...

I have an idea to fix that by changing some of the times, so I'm working on that and hope to have an answer soon...but bed first!

Last edited by phrontister (2013-02-11 10:33:54)

"The good news about computers is that they do what you tell them to do. The bad news is that they do what you tell them to do." - Ted Nelson

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## #34 2013-02-11 21:33:10

pRo9aMeR
Member
Registered: 2012-07-28
Posts: 44

### Re: Who has the purple door?

phrontister~

You've been busy the past few days I see!  I see what you've been saying and I'll give your newest version a go and see what turns out.

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## #35 2013-02-11 23:06:12

phrontister
Real Member
From: The Land of Tomorrow
Registered: 2009-07-12
Posts: 4,435

### Re: Who has the purple door?

Yes...I have been busy with it!! I've really enjoyed this puzzle, and want to help improve it if I can.

I've nearly finished revising the times (which eliminates that T&E problem I referred to in my last post), and hope to post the new version with those changes within a couple of hours if all goes well. I'm just about to have tea, and then I want to check the time changes before posting.

"The good news about computers is that they do what you tell them to do. The bad news is that they do what you tell them to do." - Ted Nelson

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## #36 2013-02-12 05:13:05

phrontister
Real Member
From: The Land of Tomorrow
Registered: 2009-07-12
Posts: 4,435

### Re: Who has the purple door?

Ok...done!

That took a lot longer than the "couple of hours" I'd mentioned, because I'd overlooked something and trying to get that right triggered off a nasty chain reaction that took quite some sorting out.

So, what I've done now is adjusted some of the starting and end times to eliminate the T&E that I mentioned earlier. I'd also got a bit mixed up with the class numbers (just a minor thing) and fixed that up too.

I got a bit tired towards the end (it's waaaay past midnight here) and didn't give my work a final check. I think - and hope - that it's all ok...but you never know! I'll do the check when I'm more awake.

If you want to keep the original title ("Who has the purple door?") as the first of the two title questions, that can easily be done by swapping two particular colours in the clues.

EDIT: There's a problem with keeping the original title, as it's important for it to somehow refer to the teacher's first name, which is solved very near the end (their surname is solved early on, and can be linked to the door colour well before their first name can). Any question that asks for their first name (I stated it) would probably be lengthier and could sound a bit awkward, I think. I haven't come up with a satisfactory alternative to the one in my 'latest version' and doubt that I will.

Last edited by phrontister (2013-02-13 11:33:49)

"The good news about computers is that they do what you tell them to do. The bad news is that they do what you tell them to do." - Ted Nelson

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## #37 2013-02-13 19:52:19

pRo9aMeR
Member
Registered: 2012-07-28
Posts: 44

### Re: Who has the purple door?

Another problem with changing the title is that now the 10th color, purple, is not metioned at all.  I see what you're saying but I'm trying to work on the in the 5-minute breaks I have inbetween my classes, that is to say that I don't have the time to devote to it right now.  I'm also in the process of moving so outside of work I have no time.  ARGH!

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## #38 2013-02-13 21:51:23

phrontister
Real Member
From: The Land of Tomorrow
Registered: 2009-07-12
Posts: 4,435

### Re: Who has the purple door?

Grumble! Got me again! I always overlook that trap!

Isn't 5 minutes between classes more than enough time?

ARGH!
Is that a Korean word? It's not in my Pocket Oxford Dictionary.

How about changing the first question to "What is the first name of the teacher with the purple door?" It's a bit lengthy, but does the job.

I'll think about it some more...

Last edited by phrontister (2013-02-13 23:09:17)

"The good news about computers is that they do what you tell them to do. The bad news is that they do what you tell them to do." - Ted Nelson

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## #39 2013-02-13 22:04:02

pRo9aMeR
Member
Registered: 2012-07-28
Posts: 44

### Re: Who has the purple door?

"argh" is how I spell the sound that Charlie Brown, one of the characters from the classic comic "Peanuts", frequently blurted out when he was frustrated.
It could also resemble the sound of a pirate, but with more of a frustrated tone.

Five minutes would be enough if I didn't also have to prepare materials for the following class

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## #40 2013-02-13 22:54:16

phrontister
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From: The Land of Tomorrow
Registered: 2009-07-12
Posts: 4,435

### Re: Who has the purple door?

It could also resemble the sound of a pirate, but with more of a frustrated tone.

Like this?

And this.

Five minutes would be enough if I didn't also have to prepare materials for the following class

Last edited by phrontister (2013-02-14 08:45:15)

"The good news about computers is that they do what you tell them to do. The bad news is that they do what you tell them to do." - Ted Nelson

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## #41 2013-02-13 23:09:34

phrontister
Real Member
From: The Land of Tomorrow
Registered: 2009-07-12
Posts: 4,435

### Re: Who has the purple door?

I'll think about it some more...

I've thought about it some more:
Hmmm...not as easy as I thought! What I said about colour swapping in post #36 has holes in it!

EDIT:
After thinking about it even more, I found an answer by increasing the number of title questions by one, to:
1. How many students are in the purple-door class?
2. What colour is David's door?
3. When does the Speaking class end?

Q1 introduces the purple door, but, as before, this question can be solved early on. Therefore we need Qs2 & 3, which can only be solved quite near the end...but how close to the end depends on the solution route.

Last edited by phrontister (2013-02-14 03:49:28)

"The good news about computers is that they do what you tell them to do. The bad news is that they do what you tell them to do." - Ted Nelson

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## #42 2013-02-16 03:09:30

phrontister
Real Member
From: The Land of Tomorrow
Registered: 2009-07-12
Posts: 4,435

### Re: Who has the purple door?

Hi pRo9aMeR,

I may have struck upon a single title question (well, two, actually; but there's only one question mark ).

I changed clue #17 to achieve that (note that the colour purple is now in the clues instead of the title question).

And, if I'm not mistaken, I think that all of the clues need to be solved with this version:

I hope this works, but I haven't checked the solution from scratch yet. I'll do that soon(ish) and report back.

"The good news about computers is that they do what you tell them to do. The bad news is that they do what you tell them to do." - Ted Nelson

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## #43 2013-02-16 12:31:03

phrontister
Real Member
From: The Land of Tomorrow
Registered: 2009-07-12
Posts: 4,435

### Re: Who has the purple door?

Ok...everything checks out fine.

So, this is my final version:

It's changed a fair bit from your original and may miss out on some features from it, but what they were I don't recall now as too much water has passed under the bridge.

Have we got there?

Last edited by phrontister (2013-02-16 13:14:00)

"The good news about computers is that they do what you tell them to do. The bad news is that they do what you tell them to do." - Ted Nelson

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## #44 2013-02-17 15:28:01

phrontister
Real Member
From: The Land of Tomorrow
Registered: 2009-07-12
Posts: 4,435

### Re: Who has the purple door?

I learnt something from my previous version that has enabled me to adjust the puzzle so that we can use the original title - "Who has the purple door?" - while requiring that the whole puzzle be solved.

Here's the update:

We must be close to publication now!

Last edited by phrontister (2013-02-18 20:33:24)

"The good news about computers is that they do what you tell them to do. The bad news is that they do what you tell them to do." - Ted Nelson

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## #45 2013-02-20 19:08:54

pRo9aMeR
Member
Registered: 2012-07-28
Posts: 44

### Re: Who has the purple door?

Excellent work phronister!
I've been sick the past week so haven't been able to do anything.  But I did finish working through your latest version and it seems legit!  Just a thought, what would happen if we take out clue 31?  I'll try and work it out and see what happens.

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## #46 2013-02-21 02:06:00

phrontister
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From: The Land of Tomorrow
Registered: 2009-07-12
Posts: 4,435

### Re: Who has the purple door?

Hi pRo9aMeR...sorry you were crook! Hope you're ok now.

what would happen if we take out clue 31?

I suspect you'd come to an impasse somewhere along the line because I tied it in with certain other clues that depend on it. Unless, of course, there's another way through that I didn't think of.

"The good news about computers is that they do what you tell them to do. The bad news is that they do what you tell them to do." - Ted Nelson

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## #47 2013-02-21 18:32:10

pRo9aMeR
Member
Registered: 2012-07-28
Posts: 44

### Re: Who has the purple door?

You're right, if we take it out then some ambiguity arises which throws everything out of whack.

I guess I'm fine with this version.  I've solved this so many times, it doesn't seem that hard anymore!

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## #48 2013-02-22 02:06:24

phrontister
Real Member
From: The Land of Tomorrow
Registered: 2009-07-12
Posts: 4,435

### Re: Who has the purple door?

I'm happy with it too, although, like you, I'm now so familiar with the puzzle that it doesn't take me long to solve either...as long as I can remember how the tricky bits go! But I think that for anyone new to the puzzle it would pose a pretty stiff challenge!

The puzzle is excellent as it is, I reckon, with a good variety of conundrums so that you need to use several different solving strategies throughout the puzzle.

At various times during my revisions I've tried dropping a clue that I thought might be superfluous, only to be blocked by an unforeseen impasse.

Bob usually does these logic puzzles but he hasn't said yet that he's solved it, so maybe he's waiting for us to settle on the final version.

Last edited by phrontister (2013-02-22 02:09:23)

"The good news about computers is that they do what you tell them to do. The bad news is that they do what you tell them to do." - Ted Nelson

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## #49 2013-02-24 18:09:59

pRo9aMeR
Member
Registered: 2012-07-28
Posts: 44

### Re: Who has the purple door?

I'm happy with it too so if MIF would post it on the website, that'd be fantastic!

And thank you phronister for helping make this an awesome Einstein puzzle!

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## #50 2013-02-24 18:50:59

phrontister
Real Member
From: The Land of Tomorrow
Registered: 2009-07-12
Posts: 4,435

### Re: Who has the purple door?

Please plant your finger on the 'Pause' button for the moment, 'cos right now I'm working on unravelling and perfecting a devious thought I've had that I hope will make life an absolute misery for any would-be solvers.

Of course, if it appears that my changes will work, I'll have to test them by solving the puzzle from scratch (again!) and ask you to do the same...again!

I'll report back soon(ish)...

"The good news about computers is that they do what you tell them to do. The bad news is that they do what you tell them to do." - Ted Nelson

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