One day, when the monks were seated at their repast, the Abbot announced
that a messenger had that morning brought news that a number of pilgrims
were on the road and would require their hospitality.
"You will put them," he said, "in the square dormitory that has two
floors with eight rooms on each floor. There must be eleven persons
sleeping on each side of the building, and twice as many on the upper
floor as on the lower floor. Of course every room must be occupied, and
you know my rule that not more than three persons may occupy the same
room."
I give a plan of the two floors, from which it will be seen that the
sixteen rooms are approached by a well staircase in the centre. After the
monks had solved this little problem and arranged for the accommodation,
the pilgrims arrived, when it was found that they were three more in
number than was at first stated. This necessitated a reconsideration of
the question, but the wily monks succeeded in getting over the new
difficulty without breaking the Abbot's rules. The curious point of this
puzzle is to discover the total number of pilgrims.