#./interaufg864_en.tex#How many possibilities do exist to arrange the digits
in a 4x4 grid if
- a)
- each digit appears 4 times, e.g.
| 1 |
1 |
1 |
1 |
| 2 |
2 |
3 |
3 |
| 4 |
2 |
2 |
3 |
| 4 |
4 |
4 |
3 |
- b)
- in addition, all digits appear in each row, e.g.
| 1 |
2 |
3 |
4 |
| 1 |
3 |
4 |
2 |
| 3 |
2 |
4 |
1 |
| 3 |
4 |
2 |
1 |
- c)
- moreover, no digit appears more than once in each column, e.g.
| 1 |
2 |
3 |
4 |
| 2 |
1 |
4 |
3 |
| 3 |
4 |
1 |
2 |
| 4 |
3 |
2 |
1 |
Fill in a grid where in addition to the constraints of a) - c) no identical digits are placed along the main diagonals.
Answer:
