For
![n](/media/m/a/e/5/ae594d7d1e46f4b979494cf8a815232b.png)
an odd positive integer, the unit squares of an
![n\times n](/media/m/1/c/a/1caee5824fd124b98d47c32a5a96cad3.png)
chessboard are coloured alternately black and white, with the four corners coloured black. A it tromino is an
![L](/media/m/f/c/1/fc1ae4eb78da7d1352cbf1f8217ab286.png)
-shape formed by three connected unit squares. For which values of
![n](/media/m/a/e/5/ae594d7d1e46f4b979494cf8a815232b.png)
is it possible to cover all the black squares with non-overlapping trominos? When it is possible, what is the minimum number of trominos needed?
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For $n$ an odd positive integer, the unit squares of an $n\times n$ chessboard are coloured alternately black and white, with the four corners coloured black. A it tromino is an $L$-shape formed by three connected unit squares. For which values of $n$ is it possible to cover all the black squares with non-overlapping trominos? When it is possible, what is the minimum number of trominos needed?