Problem 12 · 2011 Math Kangaroo
Medium
Spatial & Visual Reasoning
foldingreflection
A page is folded along the thick line as shown. Which letter will not be covered by a grey square?
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Answer: E — E
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Hint 1 of 2
Fold the grey squares across the thick line and see which lettered cells they land on.
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Hint 2 of 2
The letter that no folded grey square reaches is the answer.
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Approach: reflect the grey squares over the fold
- Folding along the thick line mirrors each grey square onto a cell on the lettered side.
- Tracking each grey square's mirror image, cells A, B, C and D each receive a grey square.
- No grey square lands on E, so E stays uncovered.
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