Školjka In a mathematical competition, in which 
problems were posed to the participants, every two of these problems were solved by more than 
of the contestants. Moreover, no contestant solved all the problems. Show that there are at least 
contestants who solved exactly 
problems each.
Radu Gologan and Dan Schwartz
problems were posed to the participants, every two of these problems were solved by more than of the contestants. Moreover, no contestant solved all the problems. Show that there are at least contestants who solved exactly problems each. Radu Gologan and Dan Schwartz