Ten women sit in 10 seats in a line. All of the 10 get up and then reseat
[FONT=CMR10][SIZE=2][FONT=CMR10][SIZE=2][LEFT]themselves using all 10 seats, each sitting in the seat she was in before or aseat next to the one she occupied before. In how many ways can the women be [SIZE=4]reseated?
Suppose that is the number of ways to seat women according to the rules.
Then and if then
Can you explain why that works?
Hint: think about using strings already used.