Puzzle Maths?

Thirteen teachers are in Paradox, New York attending a math
conference. When they arrive at the Enigma Hotel to check in, they are told that only 12 rooms are available. Since their school had made reservations for 13 rooms, the teachers are a bit upset that they will have to find another place to stay. As they are preparing to leave and find another hotel, the manager comes out and asks if there is a problem. When she hears of their situation she assures them that the Enigma Hotel has enough space to accommodate each teacher in his or her own room. She takes two of the teachers to room #1 and promises to come back in a few minutes and take one of them to another room. She takes the third teacher to room #2, the fourth teacher to room #3, the fifth teacher to room #4 and so on, taking the twelfth teacher to room #11. She then returns to room #1 and escorts the extra teacher waiting there to room #12. All of the teachers are now happily settled in their own rooms. Is this possible? Why

Very Sorry I don't Know.,
http://www.aimsedu.org/Puzzle/paradox/pa...

Ya know questions in P&S are usually a bit punchier. Too much thought for this one. My guess is one of the teachers died from waiting too long.

13th teacher never got a room
teacher 1&2 room1
teacher3 room2
teacher4 room3
teacher5 room4
teacher6 room5
teacher7 room6
teacher8 room7
teacher9 room8
teacher10 room9
teacher11 room10
teacher12 room11

then go back and escort teacher 2 to room 12


well where's teacher 13 going?

room 1 p1,2
room 2 p3
room 3 p4
room 4 p5
room 5 p6
room 6 p7
room 7 p8
room 8 p9
room 9 p10
room 10 p11
room 11 p12
room 12 p 2

But.....where is teacher 13? Ha Ha....you almost got me.......it took me a while but I got it. (ok I had to call a friend to help me)....we are both teachers so we are going to have our students try it tomorrow!