MathDB

Let

n > 1

be an integer. An

n \times n

-square is divided into

n^2

unit squares. Of these unit squares,

n

are coloured green and

n

are coloured blue, and all remaining ones are coloured white. Are there more such colourings for which there is exactly one green square in each row and exactly one blue square in each column; or colourings for which there is exactly one green square and exactly one blue square in each row?

Problem Statement