# 4 Chair Constant

You are in a room with four chairs and four people. Each chair stays ten feet away from one person (one chair per person in the group) in a constant direction (i.e. North).

Find a way to get each chair occupied(no specific order).

The chairs move with their chosen person. (Even when someone is sitting in it, but the person moving will feel the force of them pushing a chair with soneone in it)

• does this room have walls? Commented Apr 8, 2016 at 17:48
• Do the chairs continue to move when someone sits in them? Does the person move along with them? Commented Apr 8, 2016 at 17:56
• Go to the North Pole and sit in the chairs while they're confused. Commented Apr 8, 2016 at 18:03
• Are they on some planet with circumference of 40 feet? Commented Apr 8, 2016 at 18:19
• If it actually is intended as an example, the question should be edited to use e.g. instead of i.e.. i.e. means "id est", or loosely, "in other words." It is not used to provide an example, but rather to further explain something. Commented Apr 8, 2016 at 18:42

You are in a room with four chairs and four people. (...)

Find a way to get each chair occupied(no specific order).

Make the people be ten feet apart in a north-south line, so that three of them can sit in others' chairs. Now

you sit in the fourth chair, making all four chairs occupied.

• Ah!!! Nice one. I'm pretty sure this is the answer, reading the question again. I guess rtq is the magic trick here. Commented Apr 8, 2016 at 18:36
• on one hand, the lack of a "lateral thinking" tag makes me not so convinced, but it doesn't mean it's not the answer Commented Apr 8, 2016 at 19:50
• This kind of depends on whether the problem statement is parsed as "you are (in a room) with ... four people" or "you are in (a room with ... four people)". If you're with four people, there are five people total; if it's a room with four people, you're one of the four. Commented Apr 8, 2016 at 21:16
• But what if you are a chair? oO Commented Apr 9, 2016 at 10:27

Although I like the answer from f'', here's an alternate.

Put the room...

Around the North Pole. Have the four people pair up. Each pair should line up 5 feet south of the North Pole, but diametrically opposite each other. Then 10 feet "North" would extend 5 feet past the North Pole and each pair of people could sit in the other person's chair.

The obvious solution seems to be for everyone to walk north until their chairs hit the wall, and then keep walking until they each "catch up with" their chair, and sit in it.

• "(Even when someone is sitting in it, but the person moving will feel the force of them pushing a chair with soneone in it)". This kinda implies that the person will feel the force of the wall pushing against the chair, so they wouldn't be able to walk forward any more. Commented Apr 8, 2016 at 18:32

Find a way to get each chair occupied (no specific order).

No one said anything about getting each chair occupied at the same time. So let's get each chair occupied one at a time.

B sit's in A's chair, C sit's in B's chair, D sit's in C's chair. Then B gets up so that A can walk forward 40 feet to sit in D's chair (Note that A has to sidestep twice in order to do this, of course).

Now each chair has been occupied - Done!

They all start off in a row.

CCCC

1234


Now person 2 moves north 10 feet and sits in person 1's chair and person 4 moves north 10 feet and sits in person 3's chair.

C C

2 4

1 3


Now 1 and 3 walk forward and sit in the two empty chairs.

Assumption: If someone is sitting in my chair, it won't move when I move.

• That's a big assumption. (And it makes the problem pretty trivial to solve.) Commented Apr 8, 2016 at 17:57

The room is a topological projective space based on a circle, so 'North' is along the circumference of the circle.

The question doesn't say its the geographical north. So let the 4 person stand in the corners of the square. and the chairs are near the center of the square. when the person starts to walk towards the chair along the diagonal, each walking at the same speed and starts walking at the same time, the chairs won't move because they will be stopped by each other by symmetrical forces at the center of the square.

1   2

C   C
C   C

3   4


Walk toward each other and then step to the side to slide the chair under the person.

IE) 1 and 3 walk toward each other. When they are next to each other's chair, step over and sit.

• But the chairs are always to the north of the person, so you can't get this configuration set up. Commented Apr 8, 2016 at 18:30
• It doesn't say geographically they have to face north.
– huSh
Commented Apr 8, 2016 at 18:41