Every ? divides 2025, and the ?s are all different from each other. The three red ?s multiply to 2025, and the three green ?s also multiply to 2025.
Digits with a dot between them differ by 1 if the dot is white, and by a 1:2 ratio if the dot is black. Digits a knight's move apart must be different.
Solution code: Column 9
on 2. January 2025, 03:00 by cristophermoore
updated hardness
on 29. December 2024, 08:45 by cristophermoore
@Nylimb Yes, I'm worried about this year as well. We will have to keep the flame of rationality and empathy alive... and it's hard to believe we are a quarter of the way through the 21st century :-O
on 29. December 2024, 07:43 by Nylimb
Thanks. I expect 2025 to be a bad year, but at least it's a nice number.