IMC 2025
contestants 434 · problems 10 (5+5) · scale 0–10 · per-problem yesPer-problem difficulty
Day 1
Day 2
Difficulty vs discrimination
Each dot is one problem. X — how many solved it (scored ≥ 8 of 10); Y — discrimination, i.e. how well the problem told strong contestants from weak ones (score-vs-total correlation).
A good problem sits high and away from the edges. Bottom-left dots separated nobody — almost everyone failed them the same way.
Problem statistics
Same data as the Day 1 / Day 2 charts above. Add diploma cohorts to compare winners against the field.
| # | difficulty | all | disc | topics | ||||
|---|---|---|---|---|---|---|---|---|
| avg | solved | near-0 | ||||||
| Day 1 | ||||||||
| P1 | easy | 8.4 | 82% | 7% | 0.40 | polynomialsreal analysis | ||
| P2 | hard | 2.7 | 20% | 62% | 0.37 | integrationinequalities | ||
| P3 | easy | 6.3 | 57% | 22% | 0.54 | linear algebraprobability | ||
| P4 | hard | 2.9 | 23% | 62% | 0.53 | number theory | ||
| P5 | killer | 1.0 | 5% | 79% | 0.49 | combinatoricsnumber theory | ||
| Day 2 | ||||||||
| P6 | easy | 7.5 | 66% | 13% | 0.38 | real analysis | ||
| P7 | medium | 5.5 | 39% | 19% | 0.62 | number theorycombinatorics | ||
| P8 | medium | 4.9 | 42% | 31% | 0.60 | linear algebra | ||
| P9 | very hard | 1.2 | 6% | 74% | 0.54 | probability | ||
| P10 | killer | 0.2 | 1% | 96% | 0.32 | number theory | ||
A diploma-cohort cell needs at least 5 scores, else it shows “—”. How these statistics are computed →