MathDB

2

Part of 2005 Swedish Mathematical Competition

Problems(1)

Line at a Bank

Source: 2005 Swedish Mathematical Competition #2

1/6/2018
There are 12 people in a line in a bank. When the desk closes, the people form a new line at a newly opened desk. In how many ways can they do this in such a way that none of the 12 people changes his/her position in the line by more than one?
combinatoricsSweden