MathDB
Delegates around table [2011.II.12]

Source:

March 31, 2011
probabilitygeometrygeometric transformationrotationnumber theoryrelatively primecomplementary counting

Problem Statement

Nine delegates, three each from three different countries, randomly select chairs at a round table that seats nine people. Let the probability that each delegate sits next to at least one delegate from another country be mn\frac{m}{n}, where mm and nn are relatively prime positive integers. Find m+nm+n.