BrainDen.com - Brain Teasers
• 0

## Question

There is a crowd of people in a room. Each person is asked to select some other person in the room (without telling anyone). At a signal, every person tries to approach the selected person and stand behind his/her back. What patter would emerge when "the dust settles"?

## Recommended Posts

• 0

I got sort of a combination of the answers given thus far. There will be several "islands" of people, each composed of a circle of people (or just two people standing back to back) and then trees branching off the circle.

Edited by gavinksong
##### Share on other sites

• 0

The more attractive people would have more people behind their backs

##### Share on other sites

• 0

Two of them may be continuously moving in circle

##### Share on other sites

• 0

Two of them may be continuously moving in circle

Or possibly standing back to back.

##### Share on other sites

• 0

Two of them may be continuously moving in circle

Or possibly standing back to back.

on the right track. think of how stasis would look (the steady state).

##### Share on other sites

• 0

If more than two people are involved in a loop, then you might have people standing in a triangle or higher order polygon, each pointing their back toward another.

##### Share on other sites

• 0

A tree structure.

Some people would not have been chosen.
They would be the leaf nodes of the tree branches.

Note, since they have chosen someone, there are not isolated persons.

Some people would have been chosen by more than one other person.
They would be branch points.

Everyone else would have been chosen by exactly one other person.
They would form the body of each branch.

Some branches will be re-entrant (cyclical.).

##### Share on other sites

• 0

At least if you only need to stand anywhere along the line behind the chosen person, and not necessarily immediately behind them and having to squeeze in with multiple people.

##### Share on other sites

• 0

At least if you only need to stand anywhere along the line behind the chosen person, and not necessarily immediately behind them and having to squeeze in with multiple people.

Yes, it's a different result then. I took the "directly behind" interpretation.

It also took a second to see "patter" meant "pattern"

I'm thinking there is further richness (or simplicity) in the solution,

my answer was in the manner of first thoughts.

##### Share on other sites

• 0

At least if you only need to stand anywhere along the line behind the chosen person, and not necessarily immediately behind them and having to squeeze in with multiple people.

Yes, it's a different result then. I took the "directly behind" interpretation.

It also took a second to see "patter" meant "pattern"

I'm thinking there is further richness (or simplicity) in the solution,

my answer was in the manner of first thoughts.

Yes, the OP intended the individuals to move directly behind the person they identified.

The answer has been given by one of the participants here but i will hold off a little longer in siding with a particular answer to allow some additional thinking on the problem.

##### Share on other sites

• 0

Suppose someone near the "root" decided to stand behind someone on a "branch".

• 0
##### Share on other sites

• 0

k-man, do you have an equation for that?

##### Share on other sites

• 0

k-man, do you have an equation for that?

Yeah, but It took me a while to find it...

##### Share on other sites

• 0

hahaha.

Essentially what Bonanova and some others have noted about this puzzle is pretty much correct. If one were to run repeated simulations you would see this kind of hive/honeycomb formations occur with an occasional loose pieces.

##### Share on other sites

• 0

I think gavinksong's description was best.

k-man, the guy should insert a tat saying "What about" above, and "don't you understand?" below.

Looks like a proof of the Riemann Hypothesis.

## Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

×   Pasted as rich text.   Paste as plain text instead

Only 75 emoji are allowed.

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.