IMC 2014
contestants 324 · 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 | 8.9 | 88% | 3% | 0.36 | linear algebra | ||
| P2 | easy | 7.0 | 55% | 13% | 0.63 | sequences & series | ||
| P3 | medium | 4.2 | 40% | 54% | 0.53 | polynomialsreal analysis | ||
| P4 | hard | 2.7 | 25% | 63% | 0.45 | number theory | ||
| P5 | very hard | 1.0 | 5% | 78% | 0.49 | geometrycombinatorics | ||
| Day 2 | ||||||||
| P6 | easy | 8.6 | 86% | 12% | 0.38 | number theorycombinatorics | ||
| P7 | easy | 7.3 | 71% | 21% | 0.46 | linear algebrainequalities | ||
| P8 | hard | 2.2 | 18% | 65% | 0.28 | real analysisinequalities | ||
| P9 | killer | 0.6 | 4% | 89% | 0.40 | combinatoricsgeometry | ||
| P10 | very hard | 1.6 | 13% | 81% | 0.31 | combinatorics | ||
A diploma-cohort cell needs at least 5 scores, else it shows “—”. How these statistics are computed →