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ohfred
100 white and black tiles will be used to form a 10x10 square pattern. If there must be at least one black tile in every row and at least one white tile in every column, what is the maximum difference between the number of black and white tiles that can be used?

75
80
85
90
95

The attached illustration should help you understand how we arrived at the answer.

90-10 = 80

Answer is B
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Answer = B

Please refer diagram below

90 - 10 = 80

Bunuel: Kindly change the "Topic Name" from "Re: Can someone explain this tile question?" to the question...

Thanks :)
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The total of 100 white and black tiles will form a 10x10 square pattern. Each row must contain at least one black tile, and each column must contain at least one white tile. What is the maximum possible difference between the number of black and white tiles used?

A. 75
B. 80
C. 85
D. 90
E. 95


The least number of tiles of one color we can use is 10. If we place them on a diagonal of the square, both conditions are met.



The maximum difference in the number of tiles of each color is therefore, \(90 - 10 = 80\).


Answer: B
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Take any color at minimum. Min =10
Remaining = 90

difference =80
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