Problem A. 647. (September 2015)
A. 647. Let \(\displaystyle k\) be a nonnegative integer. Prove that there are only finitely many positive integers \(\displaystyle n\) for which there exist two disjoint sets \(\displaystyle A\) and \(\displaystyle B\) satisfying \(\displaystyle A \cup B = \{1; 2; \ldots; n\}\) and \(\displaystyle \displaystyle\left|\prod \limits_{a \in A} {a} - \prod\limits _{b \in B} {b}\right|=k\).
Proposed by: Balázs Maga, Budapest
(5 pont)
Deadline expired on October 12, 2015.
Statistics:
10 students sent a solution. 5 points: Baran Zsuzsanna, Gáspár Attila, Imolay András, Szabó 789 Barnabás, Williams Kada. 1 point: 3 students. 0 point: 2 students.
Problems in Mathematics of KöMaL, September 2015