[Show all top banners]

helpjava11
Replies to this thread:

More by helpjava11
What people are reading
Subscribers
:: Subscribe
Back to: Kurakani General Refresh page to view new replies
 Return of Sajha Intellects PUZZLE
[VIEWED 5261 TIMES]
SAVE! for ease of future access.
Posted on 10-29-14 11:50 AM     Reply [Subscribe]
Login in to Rate this Post:     0       ?    
 

A school exam has 23 students in 23 different classrooms. The students have no way to communicate with each other in any way from their rooms. There is another room, the play room, that has two switches on the wall (X and Y). The switches have on and off positions but they start in an unknown position.

Students are randomly taken to and from the play room one at a time. They MUST change the position of only ONE of the two switches each time they go to the room. At any point a student can yell out, "Every students has been here!" If the student is correct that all of the students have visited the play room, then they all pass the exam. If they aren't correct then they will be expelled from school.

Before they start they are given one planning session during which they can discuss a method to win the game. What method can they use to ensure they all pass?
 
Posted on 10-29-14 7:59 PM     [Snapshot: 133]     Reply [Subscribe]
Login in to Rate this Post:     0       ?    
 

Helpjava11, I like the puzzle, one question before we proceed:
Students are chosen random one at a time, but can they be repeated? Say Ram gets chosen 1st, can he be chosen in 5th turn? My guess is no.


 
Posted on 10-29-14 11:05 PM     [Snapshot: 177]     Reply [Subscribe]
Login in to Rate this Post:     0       ?    
 

Strangely this seemed very easy for about 2 minutes then got my mind 'penetrated' !!
 
Posted on 10-30-14 7:56 AM     [Snapshot: 252]     Reply [Subscribe]
Login in to Rate this Post:     0       ?    
 

Kiddo bro, yes students can be repeated as many times in random fashion. So there is no limit how many times each student are taken to the the play room.

 
Posted on 10-30-14 8:22 AM     [Snapshot: 255]     Reply [Subscribe]
Login in to Rate this Post:     0       ?    
 

Select a leader, rest are followers.
Visit by a follower:
If switch A is on, toggle switch B.
If switch A is off and you have not previously toggled switch A, and you have previously seen switch A on, toggle it on, otherwise toggle switch B.
If switch A is off and you have previously toggled switch A, toggle switch B.

Visit by the leader:
If switch A is off, toggle it on.
If switch A is on, toggle it off. If you did not turn switch A on during your previous visit, increment the count of prisoners.

Switch A states are used by leader for counting, switch B is there so that follower can toggle it if they have already toggled Switch A.

Unknown initial state is solved because only leader would initially toggle the switch A.

Don't ask how I came up with the solution, you probably would find out soon. :P

 
Posted on 10-30-14 9:50 AM     [Snapshot: 297]     Reply [Subscribe]
Login in to Rate this Post:     0       ?    
 

I find this problem as think out of the box problem and the hint is here:
The students have no way to communicate with each other in any way from their rooms.
ie; They can communicate with each other out of their room. 
How?? Each student can drop their pen or draw a line (only once) on wall. If there are 22 pens or 22 lines and if the student taken to the play room has not dropped the pen or drawn a line, s/he can scream.

"Switch" is the diversion of your mind from the main problem.

 
Posted on 10-30-14 1:36 PM     [Snapshot: 356]     Reply [Subscribe]
Login in to Rate this Post:     0       ?    
 

that was well thought of by KaliKoPoi. But they have to use only the switches and can't use anything else.
 


Please Log in! to be able to reply! If you don't have a login, please register here.

YOU CAN ALSO



IN ORDER TO POST!




Within last 30 days
Recommended Popular Threads Controvertial Threads
What are your first memories of when Nepal Television Began?
मन भित्र को पत्रै पत्र!
काेराेना सङ्क्रमणबाट बच्न Immunity बढाउन के के खाने ?How to increase immunity against COVID - 19?
TPS Work Permit/How long your took?
चितवनको होस्टलमा १३ वर्षीया शालिन पोखरेल झुण्डिएको अवस्था - बलात्कार पछि हत्याको शंका - होस्टेलहरु असुरक्षित
Nepali doctors future black or white usa ?
Another Song Playing In My Mind
nrn citizenship
TPS Renewal Reregistration
हेर अमेरिकामा नेपालीहरुको बेज्जत
WHAT DO YOU GUYS THINK ABOUT THIS?
Send Parcels from USA to Nepal & Worldwide.
Why is every youths leaving Nepal? Why are not youths entering politics and serving the country, starting business etc?
Is money sent to support family tax deductible?
Nearly one-third of Americans support autocracy, poll finds
Alert: Turbo Cancers: A Rising Global Threat
महँगो अण्डाको पिकल्प : कुखुरा र खोर भाडामा लिने
Informatica consultancy share
Travelling on TPS advance travel document to different country...
Are you ready to know the truth?
NOTE: The opinions here represent the opinions of the individual posters, and not of Sajha.com. It is not possible for sajha.com to monitor all the postings, since sajha.com merely seeks to provide a cyber location for discussing ideas and concerns related to Nepal and the Nepalis. Please send an email to admin@sajha.com using a valid email address if you want any posting to be considered for deletion. Your request will be handled on a one to one basis. Sajha.com is a service please don't abuse it. - Thanks.

Sajha.com Privacy Policy

Like us in Facebook!

↑ Back to Top
free counters