https://artofproblemsolving.com/wiki/api.php?action=feedcontributions&user=Zwmdywu&feedformat=atomAoPS Wiki - User contributions [en]2021-09-19T10:28:35ZUser contributionsMediaWiki 1.31.1https://artofproblemsolving.com/wiki/index.php?title=1971_IMO_Problems/Problem_6&diff=729531971 IMO Problems/Problem 62015-11-23T22:42:11Z<p>Zwmdywu: Created page with "Let A = (aij), where i, j = 1, 2, ... , n, be a square matrix with all aij non-negative integers. For each i, j such that aij = 0, the sum of the elements in the ith row and t..."</p>
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<div>Let A = (aij), where i, j = 1, 2, ... , n, be a square matrix with all aij non-negative integers. For each i, j such that aij = 0, the sum of the elements in the ith row and the jth column is at least n. Prove that the sum of all the elements in the matrix is at least n2/2.</div>Zwmdywu