MEMO 2025 T4
Let be a positive integer. In the province of Laplandia there are 100 cities, each two connected by a direct road, and each of these roads has a toll station collecting a positive amount of toll revenue. For each road, the revenue of its toll station is split equally between the two cities at the ends of the road (meaning that each of the two cities receives half of the income). For each city, the total toll revenue is given by the sum of the revenues it receives from the 100 toll stations on its roads.
According to a new law, the revenues of some of the toll stations will be collected by the federal government instead of by the adjacent cities. The governor of Laplandia is allowed to choose
Official text Middle European Mathematical Olympiad 2025 official paper, page 1. Quoted with source.
A model read this text from the scan of the paper by OCR, with vision/local (GLM-OCR-8bit). No person has checked it against the paper yet.
Solutions
No solution is on olymmath yet. Official and human solutions come first when they arrive. AI solutions come after them, with a label.
Similar problems
These problems have the most words in common with this statement.