MathDB
numbers 1-9 in a 3x4 table

Source: OLCOMA Costa Rica National Olympiad, Final Round, 2015 Shortlist LR2 day1 (Logic Reasoning)

September 29, 2021
combinatorics

Problem Statement

In the rectangle in the figure, we are going to write 1212 numbers from 11 to 99, so that the sum of the four numbers written in each line is the same and the sum of the three is also equal numbers in each column. Six numbers have already been written. Determine the sum of the numbers of each row and every column. https://cdn.artofproblemsolving.com/attachments/7/f/3db9ded1e703c5392f258e1608a1800760d78c.png