CombinatoricsDifficulty 6.0National OlympiadFind the answerHungary
A k×k array contains each of the numbers 1,2,…,m exactly once, with the remaining entries all zero. Suppose that all the row sums and column sums are equal. What is the smallest possible value of m if k=3n (n∈N+)?
Want a route through all this instead of an archive? The track
puts 2,000 problems in a working order, from AMC 10 level to the IMO shortlist.