MathDB
Breakfast at a Hotel

Source:

November 13, 2005
countingdistinguishabilityprobabilitynumber theoryrelatively prime

Problem Statement

A hotel packed breakfast for each of three guests. Each breakfast should have consisted of three types of rolls, one each of nut, cheese, and fruit rolls. The preparer wrapped each of the nine rolls and once wrapped, the rolls were indistinguishable from one another. She then randomly put three rolls in a bag for each of the guests. Given that the probability each guest got one roll of each type is mn\frac{m}{n}, where mm and nn are relatively prime integers, find m+nm+n.