Question 113
On a $10 \times 10$ chessboard, some $4n$ unit square fields are chosen to form a region $R$. This region $R$ can be tiled by $n$ $2 \times 2$ squares. If $R$ can also be tiled by a combination of $n$ pieces of the following types of shapes (with rotations allowed).
Determine the minimum value of $n$. (Posed by Zhu Huawei)
Determine the minimum value of $n$. (Posed by Zhu Huawei)