As Stephen Buxton said in his post, there is only ONE solution to this problem.

I will repost a different version of this puzzle. the solution is same but the making of this puzzle is bit different.

Hope I can clear out the rules and restrictions of this puzzle.

Room A is full of gnomes who all have their standard pointy hats on, but an evil sorcerer has glued all their hats to their heads and changed some of their hats from the usual red to blue... (i.e. room with N gnomes of which N - X have red hats on and X have blue.) No gnome knows the colour of his own hat

Room B is connected to room A with a door and is currently empty. Neither rooms have anything notable (like mirrors) to aid the gnomes finding out their hat colour.

The sorcerer has set a challenge - the gnomes must go one by one through the door to the other room and once all gnomes have gone through to room B they must be standing in two groups sorted by hat colour (i.e. all the reds in one group and all the blues in the other).

Unfortunately the sorcerer has also set some restrictions... The gnomes are not allowed to communicate with another in any way (no words, winks, head-shaking or anything else!).

You are allowed to help them, BUT you are allowed only one sentence to help them. You can tell this one sentence to each individual gnome or to the group as a whole. The sentence will be the same regardless of both the total number of gnomes and the proportion of gnomes with each hat colour (Assume you are telling them over an intercom!)

The sentence is short, the solution logical and it causes the gnomes to sort themselves into one group of red and one group of blue hat wearers !

Should there be a separation between the groups? If not, I think Stan solved it in the other thread with "Get in between the colors or at either end if only one color is present."

/Tomas

Just to be nit-picky, I said that I knew one solution, people may be able to come up with other methods

Are run-on sentences allowed? I was always noted as having a mastery of that particular English concept.

Nick Fox

Just say to everyone, "All the reds stand over to the right side" and the rest (the blues) get pushed back to the left side, or a shortened version. "Reds to the right."