MathDB
2015 Guts #30

Source:

August 2, 2022
2015Guts Test

Problem Statement

Suppose that 1010 mathematics teachers gather at a circular table with 2525 seats to discuss the upcoming mathematics competition. Each teacher is assigned a unique integer ID number between 11 and 1010, and the teachers arrange themselves in such a way that teachers with consecutive ID numbers are not separated by any other teacher (IDs 11 and 1010 are considered consecutive). In addition, each pair of teachers is separated by at least one empty seat. Given that seating arrangements obtained by rotation are considered identical, how many ways are there for the teachers to sit at the table?