Problem #PRU-115449
Problems
Methods
Pigeonhole principle
Pigeonhole principle (finite number of poits, lines etc.)
Discrete Mathematics
Combinatorics
Dissections, partitions, covers and tilings
Tilings with ordinary and domino tiles
Problem
On an 8×8 grid (like a chessboard), an L-corner is a shape made of 3 little squares of the board that touch to make an L. You can turn the L any way you like. We place the L-corners so that none overlap. What is the fewest L-corners you must place so that no more L-corners can be added anywhere? Here is an example of how three L-corners may look like:
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