

IQ Test Puzzle - zvanness
http://www.robmathiowetz.com/

======
madaxe_again
Wolf, corn, chicken, boat, farmer... usual shenanigans. The usual solution is
to drown the wolf, eat the chicken, and get a damned bag for the corn. In this
scenario, the correct solution is divorce and a viable criminal justice system
that doesn't require prisoners to be kept in boats with families.

~~~
Justsignedup
Best solution ever.

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z2
I'm confused. If it's a Japanese IQ test, why is the swf intro written in
traditional Chinese?

EDIT: A less lazy comment--SmallCampus.net that the game links to is a Hong
Kong website, which has a collection of puzzles. I still can't find a
reference to this being a Japanese job test though.

EDIT2: And, here's the real source.
[http://www.smallcampus.net/htmlcontent.php?channel=maths_gam...](http://www.smallcampus.net/htmlcontent.php?channel=maths_games&show_date=2001-05-03)
It's a brain teaser for elementary school children.

~~~
Xophmeister
Perhaps simply because the article's author doesn't know or can't tell the
difference and just therefore assumed it to be Japanese. There's also a link
in the game to smallcampus.net, which appears to be based in Hong Kong.

EDIT: Just saw your edit. Ignore my repetition!

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jkldotio
The link to the flash game didn't work for me so playing it in my head and not
succeeding irked me enough to look at the solution video. I wrote it up, a
spoiler follows.

When there is a free shore or one person on a shore the cop can serve as an
agent of motion as he's only inhibited by the crim, who can be put in that
free space. A free cop will let you deal with one of the kids in the problem,
the parent can then deal with the remaining kid themselves or the cop can. A
mother/father boat shuttle on either side of a cop/crim transport shifts the
criminal problem over and allows the cop's magic to be used again, but from
the opposite shore.

The cop ferries criminal over to opposite side. He then returns and ferries a
boy over and bringing the criminal back. This exploits cop/crim rule by
putting the crim alone on a bank and thus "freeing" up the cop's capacity as a
coxswain to get the boy over.

Father goes over with next boy. Both boys on the other shore now, but nobody
else is there so the father is thus freed up.

They use this freedom to get the boat back by the father returning, and then
the mother ferrying him back, and returning with the boat alone.

The cop goes over with the criminal, both stay.

The father returns the boat, goes back with the mother and she comes back
alone. This is the same as the previous mother/father move, but it's enabled
the cop and crim to come over.

The mother then takes a girl over and stays there with her. Exploiting the
fact that there is only one girl left on the original shore and thus she is
alone and no rules are violated.

The cop and the criminal come back.

The cop takes the remaining girl over, leaving the criminal alone.

The cop fetches the criminal in a final move.

Like many word problems it is beset with confusions via hidden assumptions.
The assumption that children can't be trusted with their parents and a cop is
to be trusted with children more than the parents is weird. Unsupervised
children are apparently safer than with their parents too. The assumption that
the criminal is dangerous to unprotected family members, through theft or
violence, but won't run away when left alone clouds the solution as you
intuitively don't want to leave the criminal alone even though the rule is
stated only in relation to family members.

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cpfohl
I recommend family counseling. Both Mom and Dad should be able to spend time
with their children without supervision from each other...

~~~
poopsintub
Not to mention the knock-out punches if you make a wrong move.

~~~
poopsintub
ok.

~~~
poopsintub
Well, then.

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stuartcw
No. I have had numerous interviews in Japan and never had a kind of test like
this. Maybe be one company has used this, but it is far from the norm and as
the z2 mentions, the intro is Chinese.

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Udo
I think there may be several solutions to this, one is:

P+T > P > P+S > P+T > F+S > F > F+M > M > P+T > F > F+M > M > M+D > P+T > P+D
> P > P+T

Where P=policeman T=thief S=son F=father M=mother D=daughter.

It helped me to approach this as some kind of machine, or a universe with
weird physics - from there you can establish some basic operations which are
then easy to combine into the whole solution.

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tokenadult
Blogspam for something the author plainly didn't investigate thoroughly
enough. (It's not really a job application test, it's not at all an "IQ test,"
and it's not from Japan.) I'm glad other comments here are looking at whether
the blog post is even accurate (it is not) and not reflexively responding to
headline terms like "IQ test" and "Japan," which often generate knee-jerk
responses in online discussion. Hacker News deserves better submissions than
this.

~~~
Udo
I think everybody here already arrived at that conclusion but then they got
interested in the actual puzzle.

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biggerfisch
The only solution I found involved leaving the thief alone several times - is
that not worse than leaving the thief with a family whose parents are
apparently dangerous?

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jonsen
_Pruning the search tree_ , E.W. Dijkstra:

[http://www.cs.utexas.edu/users/EWD/transcriptions/EWD12xx/EW...](http://www.cs.utexas.edu/users/EWD/transcriptions/EWD12xx/EWD1255.html)

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snorkel
One of the daughters has to bring the boat back, then the father and son cross
the river, sell the boat, then they use the proceeds to start a company
selling IQ testing services to lazy HR departments. Did I get the job?

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tzs
> The Father cannot stay with any of the daughters, without their Mother's
> presence.

> The Mother cannot stay with any of the sons, without their Father's presence

This is a bit disturbing.

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boomlinde
My prolog sense is tingling!

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iondream
this is unsolvable. the 2 sets of children that can't travel with the adults
and the police criminal pair that must be together make too many dependencies.
is this a joke?

~~~
Udo
The criminal people don't need to stay together, the thief can stay behind as
long as she is alone. You can hence use the policeman to ferry a son/daughter.
The next challenge is if you go from there and ferry one side of the family
across, eventually the boat will be on the wrong side - so you need to make a
little tedious shuttling/shuffling session to make sure the policeman/thief
duo actually waits on the opposite side. From there, it's pretty straight
forward again.

I'd say those are the only two critical sections, the rest should follow
automatically.

~~~
iondream
oh I see. it seems obvious now. odd. Thanks

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JasonFruit
I hope the description is better in Japanese: there's a difference between
'stay' and 'be'.

