[net.puzzle] job applicant puzzle

rcj@burl.UUCP (10/14/83)

Well, since I did the initial proposal for this group, I guess it is
up to me to get things rolling.  Here is a puzzle for you, with the
answer (rot 13) below it.  Enjoy!!

Three intelligent men, applying for a job, seem equal in all pertinent
attributes, so the prospective employer, also an intelligent man, sets
a simple problem for them.  The job, he says, will go to the first
applicant to solve it.  A mark is placed on each man's forehead.  The
three are told that each has either a black mark or a white mark, and
each is to raise his hand if he sees a black mark on the forehead of
either of the other two.  The first one to tell what color he has and
how he arrived at his answer will get the job.  Each man raises his
hand, and after a few seconds one man comes up with the answer.  What
color was his mark, and how did he figure it out?


SOLUTION:  (rot 13)

Tvira gung:
(n) nyy 3 zra ner bs eryngviryl rdhny vagryyvtrapr
(o) nyy 3 zra unir gurve unaqf envfrq
(p) ab bar unf fnvq gung ur xabjf gur nafjre

Pbapyhqr:
(n) Gurer pna or ab zber guna bar juvgr znex nzbat gur 3 zra, orpnhfr
    gura nyy 3 zra jbhyq abg unir gurve unaqf envfrq.
(o) Vs nal bs gur 3 zra fnj n juvgr znex ba 1 bs gur bgure zra'f sberurnqf,
    ur jbhyq vafgnagyl xabj gung uvf znex jnf oynpx orpnhfr bgurejvfr
    gur guveq zna jbhyq or frrvat 2 juvgr znexf naq jbhyq abg unir uvf
    unaq envfrq (tbrf unaq-va-unaq jvgu pbapyhfvba (n))
(p) Gurersber, fvapr ab bar unf fnvq nalguvat lrg, vg zhfg or gehr gung
    ab bar vf frrvat n juvgr znex naq gurersber gur zna jub tbg gur pbeerpg
    nafjre xarj gung uvf znex unq gb or oynpx.

Guvf ceboyrz vyyhfgengrf gur ceboyrz-fbyivat oybpx bs rkpyhfvba; gur
snpg gung gur guerr zra jrer bs nccebkvzngryl rdhny vagryyvtrapr vf jevggra
bss ol zbfg crbcyr nf zreryl n jnl gb frg hc gur ceboyrz fpranevb, naq
vf abg pbafvqrerq gb or cregvarag gb gur ceboyrz.
-- 

The MAD Programmer -- 919-228-3814 (Cornet 291)
alias: Curtis Jackson	...![ floyd clyde ihnp4 mhuxv ]!burl!rcj

mager@uw-beaver (Gary Mager) (10/17/83)

One of the applicants could have answered the question right away.  Since
the interviewer said the job would be determined by the correct answer,
it would not have been a fair test if they did not all have black marks.
Someone without a black mark could not have been the first to answer.

        Gary Mager