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• 01:14, 15 May 2021 (diff | hist) . . (+534). . N 1998 IMO Shortlist Problems/C4(Created page with "If A is a permutation of 1, 2, 3, ... , n and B is a subset of {1, 2, ... , n}, then we say that A splits B if we can find three elements of A such that the middle element doe...") (current)
• 01:13, 15 May 2021 (diff | hist) . . (+285). . N 1998 IMO Shortlist Problems/C3(Created page with "The numbers from 1 to 9 are written in an arbitrary order. A move is to reverse the order of any block of consecutive increasing or decreasing numbers. For example, a move cha...") (current)
• 01:08, 15 May 2021 (diff | hist) . . (+580). . N 1998 IMO Shortlist Problems/C2(Created page with " n is a fixed positive integer. An odd n-admissible sequence a_1, a_2, a_3, ... satisfies the following conditions: 1 : a_1 = 1. 2 : a_2k = a_2k-1 + 2 or a_2k-1 + n 3 : a_2k+...") (current)
• 01:05, 15 May 2021 (diff | hist) . . (+195). . N 1998 IMO Shortlist Problems/C1(Created page with " An m x n array of real numbers has the sum of each row and column integral. Show that each non-integral element x can be changed to [x] or [x] + 1, so that the row and column...") (current)