What numbers should replace the question marks?
Every question mark can be replaced by digit from set {1,2,3,4,5,6,7,8}.
5 | 7 | 8 | 6 | 8 | 6 |
8 | 6 | 3 | ? | 7 | 4 |
2 | ? | 7 | 8 | 6 | 8 |
5 | 8 | ? | 4 | 5 | ? |
3 | 1 | 7 | 2 | 8 | 6 |
7 | 4 | 8 | 5 | 7 | 3 |
Source: The Complete Book of Intelligence Tests: 500 Exercises to Improve, Upgrade and Enhance Your Mind Strength by Philip Cartez