We all have an affinity for the problems shared by staff. Of course these are the problems created by the experts of Brilliant. But due to introduction of \(Brilliant^2\), most of these admirable problems were made unavailable to non-\(B^2\) members. I even had asked the staff the reasons for this, but got no reply. Even my comments in other members' posts about the issue were deleted by the staff. Many of the genius Brilliant users haven't upgraded.
So I took a step to filter out the free problems from the paid ones and have saved them into these three sets according to the problems created by David Mattingly, Calvin Lin and Arron Kau.I've taken hours to arrange the problems. All the problems are arranged in the order of levels. This note will also serve as an introductory note to each of the above mentioned sets.
If someone finds a new (free) problem or a (free) problem that hasn't yet been added, please comment that link here and I'll save them into my sets accordingly. Please like, share and comment if you want to see more problems added. But above all, enjoy solving free problems by the staff!