Problem 13 · 2021 Math Kangaroo
Medium
Spatial & Visual Reasoning
path-tracing
Rosa wants to start at the arrow, follow the line, and get out at the other arrow. Which piece is it NOT possible to put in the middle to obtain that?
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Answer: D
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Hint 1 of 2
The middle piece must connect the line entering it to the line leaving it within the surrounding grid.
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Hint 2 of 2
Check each candidate's openings against the fixed track around the centre; one cannot link them up.
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Approach: match the centre piece's connections to the fixed track
- The path must enter the centre square and leave it so the whole route runs from arrow to arrow.
- The surrounding cells fix which sides of the centre the line must touch.
- Piece D cannot join those required sides, so it is the impossible one.
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