MathDB
Find all possible values of m, n

Source: China TST 2011 - Quiz 2 - D1 - P2

May 20, 2011
calculusderivativefunctionalgebrapolynomialmodular arithmeticcombinatorics unsolved

Problem Statement

Let \ell be a positive integer, and let m,nm,n be positive integers with mnm\geq n, such that A1,A2,,Am,B1,,BmA_1,A_2,\cdots,A_m,B_1,\cdots,B_m are m+nm+n pairwise distinct subsets of the set {1,2,,}\{1,2,\cdots,\ell\}. It is known that AiΔBjA_i\Delta B_j are pairwise distinct, 1im,1jn1\leq i\leq m, 1\leq j\leq n, and runs over all nonempty subsets of {1,2,,}\{1,2,\cdots,\ell\}. Find all possible values of m,nm,n.