Downtime Puzzle, again

[katleoyumi]

I think C is the liar because:

A knows 6 other people so:
A = BCDEFG

G knows 1 person so:
G = A

B knows 5 people so:
B = ACDEF (because B cannot know G since G only knows one person aka A who knows everyone)

E and F only know 2 people and since B and A both know E and F, that means:
E = AB
F = AB

D only knows 3 people, and D cannot possibly know G, E, or F, therefore:
D = ABC

C CLAIMS to know 4 people, but cannot possibly know G, F, and E, therefore:
C = ABD_

C is missing one person so therefore C is the liar.

[Galt]

Kind of late, linh. D:

But you are correct, so you can have a cookie.

[Cute]

GM-Ayu Wrote:Though my solution is much shorter:

"Every meeting must produce 2 acquaintanceships. If they are telling the truth, then there is an odd number of acquaintanceships. This is a contradiction."

I didn't get this. lol.

[GM-Ayu]

Question 2: 5 Rainbow Cake, 5 GB OCA

Suppose that you meet up with 8 new novices to explore the world of heRO. Because they were nubs and is not used to a low rate, they didn't go through training ground to get some free stuff. They all want to be assassins one day (because we all know that sins are pwnage?) but they are not used to how to walk to town of Morroc on foot, as they are corrupted by high rate free teleports. Although you can give them zeny to teleport by kafra, it doesn't help them in the long run though if they don't know their way around. So you decide to lead them by foot to travel to Morroc.

With 8 new novices, you arrive at a 4 way intersection. Then you realized that you really haven't walked on foot through Sograt to get to Morroc either, and you forgot that we actually have a world map ingame. You don't want to lose face in front of the novices to say that you need to alt-tab to find a world map though.

You know that one of the 4 proposed paths will lead to morroc for sure. It should only be a 1 minute walk to get there, counting the time to avoid monsters and all. So in theory, it's possible to all travel one path in one minute, and if you realize it's wrong, it'll take another one minute to get back to this intersection point (and of course, you may also participate in this walk to find Morroc as well). Then, you can go on another path to try again until you find Morroc. However, to do this task efficiently, it's best to divide the group into smaller groups, take 1 minute to travel down one path, rendezvous at the intersection in 2 minutes, then the group will know which path to take by the 3rd minute.

Problem is, 2 of these novices are mischievous and sometimes lie. You don't know who they are, and they may not always lie either (they got the ABILITY to lie.)

Find a method to guarantee that you will always find out which path leads to Morroc and arrive in Morroc within 3 minutes. State your method and reasoning for why the method works. Assume that you are not a fat retard who lie to yourself about what you find (aka, you yourself, will always tell the truth.)

[GM-Ayu]

Cute Wrote:

GM-Ayu Wrote:Though my solution is much shorter:

"Every meeting must produce 2 acquaintanceships. If they are telling the truth, then there is an odd number of acquaintanceships. This is a contradiction."

I didn't get this. lol.

If you and I meet up, we have one meeting.

I'll say "I'm now acquainted with Cute." (met 1 person)
You'll say "I'm now acquainted with Ayu." (met 1 person)
Total acquaintanceship: 2

Say the you also met up with Galt as well. now there's 2 meetings.

I'll say "I'm now acquainted with Cute." (met 1 person)
You'll say "I'm now acquainted with Ayu and Galt." (met 2 people)
Galt will say "I'm now acquainted with Cute." (met 1 person)
Total acquaintanceship: 4


So you see that as you increase the number of meetings by 1, total of the acquaintanceship always go up by unit of 2 though. So, it's impossible to have an acquaintanceship of an odd amount. Someone must be lying.

[SeifuSnow]

Yes, it's very possible. Be a good player and teach them that the best way to get somewhere is by asking a priest for a warp! (And actually, I gave up on this one. >.< )

Edit: (Not for credit, I just want to guess.)

4 groups, 9 people, 2 people per group with you tagging along with one of the groups. Send them all out and meet back and discuss what you found, then switch paths? Even if two of them lie, they still want to get to their destination, and even THEN, after the third minute, you've had a 75% chance of finding the third path. If you hadn't found it, it'd obviously be the one that you hadn't found anything at yourself.

Edit2: OH SNAP! Logic has failed me. I forgot about walking back. xD This is so not my time to think. *thinks* "If the world were to go into mass panic and I was left the make a dire decision RIGHT now, we would all be doomed."

[Ellie]

Imma be evil here.

It is -possible-. Not always 100% guaranteed, but it is possible.
If they all go out, 1min. If they all come back, 1min. If none of them lie, you all walk to Morroc. 1min. We'd have to assume that the -within- 3 minutes means less than or equal too, though. =P

English: Take that, maths!

<3 Loopoles.

[Cute]

GM-Ayu Wrote:If you and I meet up, we have one meeting.

I'll say "I'm now acquainted with Cute." (met 1 person)
You'll say "I'm now acquainted with Ayu." (met 1 person)
Total acquaintanceship: 2

Say the you also met up with Galt as well. now there's 2 meetings.

I'll say "I'm now acquainted with Cute." (met 1 person)
You'll say "I'm now acquainted with Ayu and Galt." (met 2 people)
Galt will say "I'm now acquainted with Cute." (met 1 person)
Total acquaintanceship: 4


So you see that as you increase the number of meetings by 1, total of the acquaintanceship always go up by unit of 2 though. So, it's impossible to have an acquaintanceship of an odd amount. Someone must be lying.

Thanks.

[GM-Ayu]

Ellie Wrote:Imma be evil here.

It is -possible-. Not always 100% guaranteed, but it is possible.
If they all go out, 1min. If they all come back, 1min. If none of them lie, you all walk to Morroc. 1min. We'd have to assume that the -within- 3 minutes means less than or equal too, though. =P

English: Take that, maths!

<3 Loopoles.

And in my own thread, I said that only players cannot edit.

Therefore:

Edit button: Take that, English!


(I'll allow you to make a 2nd post to find the 'real method' )

[Ellie]

4 paths, 9 people.

Split into groups of 3, and each lot of people take a path. (you do not need to search all 4 paths at once, as if none of the 3 searched are found to be Morroc, it can only be the 4th.)

This means that if they find it, and someone lies, then none of the other parties will be able to have all 3 people say they found it, as there is only one liar left (at best, you could get a 2-notfoundvs1 found).
If you get both liars in the same group, and get a 2-found vs1notfound, then another group will have all 3 saying they found it.

If you get 2 liars in the finding group saying they did not find it, then the above works, as the other groups will be filled of 3 people saying they did now find it.