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UKMT Junior Mathematical Challenge, 2019

Combinatorics Difficulty 2.0 Junior Find the answer United Kingdom

All four L-shapes shown in the diagram are to be placed in the $4$ by $4$ grid so that all sixteen cells are covered and there is no overlap. Each piece can be rotated or reflected before being placed and the black dot is visible from both sides. How many of the $16$ cells of the grid could contain the black dot?

(A) $4$ (B) $7$ (C) $8$ (D) $12$ (E) $16$

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