MathDB
IMO LongList 1967, Mongolia 2

Source: IMO LongList 1967, Mongolia 2

December 16, 2004
combinatoricscounting

Problem Statement

An urn contains balls of kk different colors; there are nin_i balls of ithi-th color. Balls are selected at random from the urn, one by one, without replacement, until among the selected balls mm balls of the same color appear. Find the greatest number of selections.