536 Puzzles and Curious Problems

Miscellaneous Combinatorial Puzzles 177

in paper or cardboard, and color them according to taste, but the order of the

colors must be exactly as shown in the illustration.

461. THE THIRTY-SIX
     LETTER PUZZLE

If you try to fill up this square by

repeating the letters A, B, C, D, E, F,

so that no A shall be in a line, across,

downwards or diagonally, with an-

other A, no B with another B, no C

with another C, and so on, you will

find that it is impossible to get in all

the thirty-six letters under these con-

ditions.

The puzzle is to place as many let-

ters as possible. Probably the reader

A .B C D E F

will leave more blank spaces than

there need be.

462. THE TEN BARRELS

A merchant had ten barrels of sugar, which he placed in the form of a
pyramid, as shown on following page. Every barrel bore a different number,
except one, which was not marked. It will be seen that he had accidentally