Puzzles will be deleted after one school semester (from publish date).
Puzzles
08-07-17
You and your friend are playing a game on a round table. There is an infinite supply of identical quarters which you use for the game. You and your friend will take turns placing quarters onto the table (assuming the table can hold more than 50 quarters), and the winner will be the one who places the final quarter (that is, the last quarter that makes it impossible for your friend to put down another quarter), thus completely filling the table. You cannot place quarters on top of other quarters, but you may and must place the quarter anywhere on the table. The quarter must be flat on the table. To guarantee a win, who should go first, and what is the optimal strategy?
You and your friend are playing a game on a round table. There is an infinite supply of identical quarters which you use for the game. You and your friend will take turns placing quarters onto the table (assuming the table can hold more than 50 quarters), and the winner will be the one who places the final quarter (that is, the last quarter that makes it impossible for your friend to put down another quarter), thus completely filling the table. You cannot place quarters on top of other quarters, but you may and must place the quarter anywhere on the table. The quarter must be flat on the table. To guarantee a win, who should go first, and what is the optimal strategy?
Solution:
You want to go first. Let's consider the table. Since it is a circular table, we can essentially "mirror" your friend's move--except for one spot: the middle of the board. By placing a quarter in the middle of the board, your friend must move somewhere else, and the optimal strategy is to mirror the move.
You want to go first. Let's consider the table. Since it is a circular table, we can essentially "mirror" your friend's move--except for one spot: the middle of the board. By placing a quarter in the middle of the board, your friend must move somewhere else, and the optimal strategy is to mirror the move.
Placement Test Solutions
rmc_novice_solutions.pdf | |
File Size: | 270 kb |
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rmc_intermediate_solutions.pdf | |
File Size: | 417 kb |
File Type: |
rmc_advanced_solutions.pdf | |
File Size: | 455 kb |
File Type: |
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Math Contest Information
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