Problem 22 · 2012 Math Kangaroo
Stretch
Logic & Word Problems
careful-countingcasework
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Answer: D
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Hint 1 of 2
The border numbers tell how many red squares are in each row and column.
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Hint 2 of 2
Test each option: the red squares you place must match every row total and every column total at once.
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Approach: check the row and column counts against each grid
- Each bottom number is the count of red squares in that column; each left number is the count in that row.
- A valid grid needs a red-square placement matching all four row totals and all four column totals at the same time.
- Only option D has totals that can be realised consistently.
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