Answer.—As below.
| 4 | 9 | 2 |
| 3 | 5 | 7 |
| 8 | 1 | 6 |
How may the first 16 digits be arranged so that the sum of the vertical, the horizontal, and the two oblique rows may equal 34?
Answer.—As below.
| 1 | 16 | 11 | 6 |
| 13 | 4 | 7 | 10 |
| 8 | 9 | 14 | 3 |
| 12 | 5 | 2 | 15 |
In what manner may the first 25 digits be arranged so that the sum of each row of five figures may equal 65?
Answer.—As below.
| 1 | 10 | 12 | 18 | 24 |
| 9 | 11 | 20 | 22 | 3 |
| 13 | 19 | 21 | 5 | 7 |
| 17 | 23 | 4 | 6 | 15 |
| 25 | 2 | 8 | 14 | 16 |
An old Jew took a diamond cross to a jeweler to have the diamonds reset, and fearing the jeweler might be dishonest, he counted the diamonds and found that they numbered 7 in three different ways. Now the jeweler stole two diamonds, but arranged the remainder so that they counted 7 each way as before. How was it done?
| Fig. 1. | Fig. 2. |
| 7 | 7 |
| 6 | 7 6 7 |
| 7 6 5 6 7 | 5 |
| 4 | 4 |
| 3 | 3 |
| 2 | 2 |
| 1 | 1 |