Problem 21 · 2021 Math Kangaroo
Stretch
Logic & Word Problems
casework
Ann, Bob, Carina, Dan and Ed are sitting at a round table. Ann is not next to Bob, Dan is next to Ed, and Bob is not next to Dan. Which two people are sitting next to Carina?
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Answer: A — Ann and Bob
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Hint 1 of 2
Place the people around the circle using 'Dan next to Ed' first, then apply the 'not next to' rules.
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Hint 2 of 2
Once the seating is forced, read off Carina's two neighbours.
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Approach: fix the circular order from the clues
- Dan sits next to Ed; Bob is not next to Dan and Ann is not next to Bob.
- Working these around the five-seat circle forces an order where Carina sits between Ann and Bob.
- So Carina's neighbours are Ann and Bob.
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