An interesting question !

Status
Not open for further replies.
T

taruntokas

New member
There is a community of red and blue eyed people.Every evening they meet at
a ground.Everyone can see every other person's eyes but cannot see eyes of
his own.
and no one can tell anyone what is the colour of his eyes.
As soon as a person knows that he is red eyed, he commits suicide.
If the no. of red eyed people is "r" and no. of blue eyed people is "b" in
total "r+b" ppl ...in how many days will all the red eyed people commit
suicide????
 
I think in the r Days......................

I can explain if my answer is correct
 
ya ur answer is correct....did u figure this out by urself or u heard of it b4...i was not expectin the correct response so early.
neways kudos man u got it.
hw abt explainin a bit.
 
question is simple...........

there r b person's with blue eyes.......
everyday evryone counts ....For a red eye person the count is r-1 + b so its obvious that his eyes are red & he commit suicide..........so one suicide per day....

as there r r man's with red eyes so this procedure will ends in r days....

.

tarun (Jul 12, 2004 02:57 a.m.):
ya ur answer is correct....did u figure this out by urself or u heard of it b4...i was not expectin the correct response so early.
neways kudos man u got it.
hw abt explainin a bit.
Click to expand...
 
sorry dude but ur logic isnt correct.
the catch is that the red and blue eyed ppl dont know how many of them are red eyed or otherwise. had they known they wud have counted and ended up committin suicide the very first day.
try it once more
gud luk
 
heres my logic...
all the red eyes commit sucide on the r th day.
On day 1, everyone counts the #of red and blue eyes they see.
A red guy will count r-1 reds and b blues.
A blue guy will count r reds and b-1 blues.
So, a red eye will wait for r-1 days and when the count does not change, the red eye will commit sucide the next day. A blue eye will not since he will be waiting for 1 more day...and so on.
 
ya anil u r right. but lemme put the explanation in simple words. here it goes.

it'll take r days to suicide all of them.

here i m assuming that atleast one people is red eyed in them.
now since all of them meets every evening, assume all red eyed people are
smart enough.
so now if there is only 1 red eyed people then he will see that all other
people are blue eyed, so as there is atleast one red eyed,he'll know that he
is red eyed, so in the first day he'll suicide.

now suppose 2 are red eyed. now both red eyed will see that there is one red
eyed person, since both of them dont know the color of own's eyes. now when
next day they will meet, they both will see that second person has not
suicided, so both will be knowing that he also has red eyed. so in that day
both will suicide.

so in the same way assume r red eyed people will suicide in r days, so for
r+1 red eyed people every red eyed people will see that there are "r" red
eyed people, but when on r+1th day they see that all people are there so all
r+1 red eyed people will come to know that they are red eyed, so they all
will suicide.
 
going by this logic they should all commit suicide on the 2nd day when they see that there are same no of red eyed people as yesterday.
 
lolz u didnt get it.
imagine there r 3 red eyed ppl. now the crux is that they dont know the count.
first day each one sees other 2 red eyed ppl n rest blue eyed ones. he cant make up abt himself. next day he sees other 2 red eyed again n so do the other 2. still none can make out anything. on the 3rd day also all 3 meet. now this guys applies the logic that had he been blue eyed and thus only 2 red eyed in thhe group, the two wud have commited suicide on the second day itself. so this time all 3 of them infers their identity and commit suicide.
same goes for r number of ppl

may sound confusing a bit but give it a thought and go thru my previous posting again. it took me too a while to get the trick.
 
Status
Not open for further replies.
Back
Top