The illustration is
a prison of sixteen
The locations of the ten prisoners will be seen.
The jailer has queer superstitions about odd and even numbers, and
rearrange the ten prisoners so that there shall be as many even rows of
men, vertically, horizontally, and diagonally, as possible.
At present it will be seen, as indicated by the arrows, that there are
such rows of 2 and 4.
The greatest number of such rows that is possible is sixteen.
But the jailer only allows four men to be removed to other cells, and
informs me that, as the man who is seated in the bottom right-hand
corner is infirm, he must not be moved.
How are we to get
those sixteen rows of even
numbers under such conditions?