Problem 2 · 2018 Math Kangaroo
Medium
Spatial & Visual Reasoning
path-tracing
The rings shown are partially interlinked. How long is the longest chain built this way which also contains the thick light ring?
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Answer: C — 5
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Hint 1 of 2
A chain is a run of rings where each one is linked to the next.
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Hint 2 of 2
Start from the thick light ring and follow the links as far as they continue in each direction.
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Approach: trace the longest connected run of rings through the light ring
- Two rings belong to the same chain only when they are actually interlinked.
- Beginning at the thick light ring, follow the interlinked rings outward in both directions.
- The longest such run that includes the light ring contains 5 rings.
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