Problem 3 (Geometry) was noted for its "attackability" through multiple different methods, including classic Euclidean geometry, vectors, and coordinate geometry.
This problem involved minimizing a specific expression given the constraint Comentarii JBMO 2015
The competition consisted of four problems covering algebra, number theory, geometry, and combinatorics. Problem 3 (Geometry) was noted for its "attackability"
Problem 1 was criticized for being perhaps too simple for an international olympiad, acting more as a "points booster" than a differentiator for top talent. including classic Euclidean geometry
Participants had to find prime numbers and an integer satisfying the equation
For further analysis, you can explore the full JBMO 2015 solutions and commentaries provided by the Viitori Olimpici platform. JBMO 2015 Problems and Solutions | PDF | Mathematics