The Convent Puzzle.
This puzzle is a translation from the French, and is over two hundred years old.
In a certain convent were nine cells, of which all but the central one were occupied by nuns. An abbess resided in the middle room, and visited the eight cells at regular intervals, to make sure that the sisters were keeping their vows, and each time found three nuns in each cell, which made nine in every row. Four nuns went out, however, but the abbess on her second round still found nine in a row. The four nuns now came back, each bringing a friend, and the good abbess still had no misgivings when she found the same number in each row as before. Four more friends were introduced, and still the correct number was found in the cells. How was all this possible? The answer to this puzzle will be published later on.
Vincent V. M. Beede.