398 Answersshould have had merely to exchange that rrussmg number with a blank
wherever found. There would thus have been no puzzle. But in the circum-
stances it is impossible to avail oneself of such a simple maneuver.
[For more domino problems of this type, known as quadrilles, see Edouard
Lucas, Recreations Mathematiques, Vol. 2, pp. 52-63, and Wade E. Philpott,
"Quadrilles," in Recreational Mathematics Magazine, No. 14, January-
February 1964, pp. 5-11.-M. G.]- DOMINO FRAMES
· ,
- •
•
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- •
- •
- • •
- • r-------,---'--i
- I. '···1·· •••••
- •
f--• •
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f-;-; • •
· • •.
• •• • · • • I. •• ~I· • I
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f--• • --
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The three diagrams show a solution. The sum of all the pips is 132. One-
third of this is 44. First divide the dominoes into any three groups of 44 pips
each. Then, if we decide to try 12 for the sum of the sides, 4 times 12 being 4
more than 44, we must arrange in every case that the four corners in a frame
shall sum to 4. The rest is done by trial and exchanges from one group
to another of dominoes containing an equal number of pips.