Problem B. 4725. (September 2015)
B. 4725. Show that if a simple graph has 7 vertices and no cycle of length 4 then it has a vertex whose degree is at most 2.
(4 pont)
Deadline expired on 12 October 2015.
Statistics:
159 students sent a solution.  
4 points:  119 students. 
3 points:  15 students. 
2 points:  8 students. 
1 point:  12 students. 
0 point:  3 students. 
Unfair, not evaluated:  1 solution. 
Unfair, not evaluated:  1 solution. 
