MathDB
Delegates to an Economic Conferece

Source: 2015 AIME I Problem 2

March 20, 2015
AMCAIMEAIME I

Problem Statement

The nine delegates to the Economic Cooperation Conference include 2 officials from Mexico, 3 officials from Canada, and 4 officials from the United States. During the opening session, three of the delegates fall asleep. Assuming that the three sleepers were determined randomly, the probability that exactly two of the sleepers are from the same country is mn\tfrac{m}{n}, where mm and nn are relatively prime positive integers. Find m+nm+n.