Mathematical_Recreations-Kraitchik-2e

320 Mathematical Recreations
as that shown in Figure 180. If these four five-letter words
have no literary merit, at least they have the useful property
of containing ten pairs of repeated letters so arranged as to
have each pair uniquely determined by the row or rows in
which it lies. Hence the pairs of cards may be distributed
M U T U S
D E D I T
NOM E N
C 0 CIS
FIGURE 180.
according to this pattern, and the selected pair determined
from memory. This has the advantage of giving a less reg-
LAN A T A
LEV E T E
L I V I N I
NOV 0 T 0
FIGURE 181.
ular distribution than the first scheme, so it is harder for the
victim to guess the method.
By using the set of words in Figure 181 one may guess a
set of three out of 8 sets of three cards, in a similar manner.
13. From a pack of 32 cards deal four piles face down, one
card to each pile in turn. Place the first pile on the second,
these on the third, and these on the fourth. Without cutting
or shuffling, deal as before. When the cards have been picked