MathDB
Find the greatest number of X's that can be put on the grid

Source: MTRP 2015 Class 11-Multiple Choice Question: Problem 4 :-

September 21, 2020
combinatoricsalgebra

Problem Statement

Let nn be an odd integer. Placing no more than one XX in each cell of a n×nn \times n grid, what is the greatest number of XX 's that can be put on the grid without getting nn XX's together vertically, horizontally or diagonally?
[*] 2(n2)2{{n}\choose {2}}
[*] (n2){{n}\choose {2}}
[*] 2n2n
[*] 2(n2)−12{{n}\choose {2}}-1
Back to ProblemsView on AoPS