Show as many cards to each person as there are persons to choose; that
is to say, 3 to each, if there are three persons. When the first has
thought of one, lay aside the three cards in which he has made his
choice. Present the same number to the second person, to think of one,
and lay aside the three cards in the like manner. Having done the same
in regard to the third person, arrange all these cards in three rows,
with their faces turned downwards, and then put them together in order.
If you take the 3 first, and present them successively to the different
persons, and do the same thing with the others, you may easily guess the
cards, by observing, that the card thought of by each person will have
the same place among the cards as the person has in regard to the other
two; that is to say, the card thought of by the first person will be
first of that packet in which he discovered it; that thought of by the
second will be the second in the packet where he recognized it; and that
of the third will be the last and in the last packet.
The operation is exactly the same when the number of persons is greater.
If, instead of 3, there are 4 or 5 persons, four or five cards must be
presented to each.