It is possible to place 7 cigarettes in such a way that each touches every other if 
(Gardner 1959, p. 115).
Cigarettes
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References
Gardner, M. Hexaflexagons and Other Mathematical Diversions: The First Scientific American Book of Puzzles and Games. New York: Simon and Schuster, 1959.Referenced on Wolfram|Alpha
CigarettesCite this as:
Weisstein, Eric W. "Cigarettes." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/Cigarettes.html