102.--_A Reversible Magic Square._

Can you construct a square of sixteen different numbers so that it shall

be magic (that is, adding up alike in the four rows, four columns, and

two diagonals), whether you turn the diagram upside down or not? You must

not use a 3, 4, or 5, as these figures will not reverse; but a 6 may

become a 9 when reversed, a 9 a 6, a 7 a 2, and a 2 a 7. The 1, 8, and 0

will read the same both ways. Remember that the constant must not be

changed by the reversal.

The Canterbury Puzzles, and Other Curious Problems · 第 135 / 286 题