MathDB

4

Part of 2016 Junior Balkan MO

Problems(1)

JBMO 2016 Problem 4

Source:

6/26/2016
A 5×55 \times 5 table is called regular f each of its cells contains one of four pairwise distinct real numbers,such that each of them occurs exactly one in every 2×22 \times 2 subtable.The sum of all numbers of a regular table is called the total sum of the table.With any four numbers,one constructs all possible regular tables,computes their total sums and counts the distinct outcomes.Determine the maximum possible count.
combinatorics