Problem C. 1273. (February 2015)
C. 1273. Prove that \(\displaystyle 3^{4n}+4\cdot 7^{4k}\) is divisible by 5 for all \(\displaystyle n,k\in \mathbb{N}\).
(5 pont)
Deadline expired on 10 March 2015.
Statistics:
145 students sent a solution.  
5 points:  54 students. 
4 points:  45 students. 
3 points:  37 students. 
2 points:  5 students. 
1 point:  1 student. 
0 point:  2 students. 
Unfair, not evaluated:  1 solution. 
