Difference between revisions of "Mock AIME 2 2006-2007 Problems/Problem 15"
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In order to solve this we must first look at the 2D problem: | In order to solve this we must first look at the 2D problem: | ||
− | [[Image:AIME_2006_P15b.png]] | + | [[Image:AIME_2006_P15b.png|300px]] |
In order to have exactly one red in each column and exactly one red in each row, one can select any square red in the first column, for the second column we can only chose from 3 to paint red, the third column we can only chose 2 and the last one we can only chose 1. | In order to have exactly one red in each column and exactly one red in each row, one can select any square red in the first column, for the second column we can only chose from 3 to paint red, the third column we can only chose 2 and the last one we can only chose 1. |
Revision as of 20:39, 22 November 2023
Contents
Problem
A cube is composed of unit cubes. The faces of unit cubes are colored red. An arrangement of the cubes is "intriguing" if there is exactly red unit cube in every rectangular box composed of unit cubes. Determine the number of "intriguing" colorings.
Solution
In order to solve this we must first look at the 2D problem:
In order to have exactly one red in each column and exactly one red in each row, one can select any square red in the first column, for the second column we can only chose from 3 to paint red, the third column we can only chose 2 and the last one we can only chose 1.
Therefore the total numbers of squares that can have exactly one red in each column and exactly one red in each row and one red in each row is exactly
See Also
Mock AIME 2 2006-2007 (Problems, Source) | ||
Preceded by Problem 14 |
Followed by Last Question | |
1 • 2 • 3 • 4 • 5 • 6 • 7 • 8 • 9 • 10 • 11 • 12 • 13 • 14 • 15 |