We have a set of 9 coins equally sized and shaped but with a different weight for each of them.
We also have a very new three-pan balance which work in the following way:
Three slots in which you may put coins, if one of the slot is lighter than the two other it will go up, the heavier will go down and the medium-weighted will stay at a central position. This mechanism was also describe in this question
Can you give the minimum number of weighting you will need to order your coins by weight?
For the moment the best answer was given by Bass in a certain number of move can we achieve to make it with one less move?
Source: Diophante.fr A726