By following this method, he will infallibly attain
to 89; and it will then be impossible for the second to prevent him
from getting first to 100; for whatever number the second takes, he
can attain only to 99; after which the first may say--"and 1 makes
100." If the second take 1 after 89, it would make 90, and his adversary
would finish by saying--"and 10 makes 100." Between two persons who
are equally acquainted with the game, he who begins must necessarily
win.
TO GUESS THE MISSING FIGURE
To tell the figure a person has struck out of the sum of two given
numbers: Arbitrarily command those numbers only, that are divisible
by 9; such, for instance, as 36, 63, 81, 117, 126, 162, 261, 360, 315,
and 432. Then let a person choose any two of these numbers; and, after
adding them together in his mind, strike out from the sum any one of
the figures he pleases. After he has so done, desire him to tell you
the sum of the remaining figures; and it follows, that the number which
you are obliged to add to this amount, in order to make it 9 or 18,
is the one he struck out. Thus:--Suppose he chooses the numbers 162
and 261, making altogether 423, and that he strike out the center
figure; the two other figures will, added together, make 7, which, to
make nine, requires 2, the number struck out.
Pages:
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194