Knights at the Round Table
Source:
March 13, 2004
probabilitygeometric transformationrotationcomplementary counting
Problem Statement
Twenty five of King Arthur's knights are seated at their customary round table. Three of them are chosen - all choices of three being equally likely - and are sent off to slay a troublesome dragon. Let be the probability that at least two of the three had been sitting next to each other. If is written as a fraction in lowest terms, what is the sum of the numerator and denominator?