Solution

(related to Problem: The City Luncheons)

The men may be grouped as follows, where each line represents a day and each column a table:—

$$\begin{array}{cccccc} AB&CD&EF&GH&IJ&KL\\ AE&DL&GK&FI&CB&HJ\\ AG&LJ&FH&KC&DE&IB\\ AF&JB&KI&HD&LG&CE\\ AK&BE&HC&IL&JF&DG\\ AH&EG&ID&CJ&BK&LF\\ AI&GF&CL&DB&EH&JK\\ AC&FK&DJ&LE&GI&BH\\ AD&KH&LB&JG&FC&EI\\ AL&HI&JE&BF&KD&GC\\ AJ&IC&BG&EK&HL&FD \end{array}$$` Note that in every column (except in the case of the$A$'s) all the letters descend cyclically in the same order,$B, E, G, F,$up to$J,$which is followed by$B.$`


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References

Project Gutenberg

  1. Dudeney, H. E.: "Amusements in Mathematics", The Authors' Club, 1917

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