IMC 2019
contestants
360
problems
10 (5+5)
score scale
0–10
per-problem results
yes
Notes on this edition’s data
- Each problem marked out of 10.
Per-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.
| # | difficulty | avg | solved | near-0 | disc | topics | |
|---|---|---|---|---|---|---|---|
| Day 1 | |||||||
| P1 | easy | 6.9 | 54% | 16% | 0.47 | sequences & series | |
| P2 | medium | 6.1 | 44% | 13% | 0.38 | linear algebranumber theory | |
| P3 | medium | 5.3 | 41% | 27% | 0.48 | integrationinequalities | |
| P4 | killer | 0.4 | 2% | 92% | 0.33 | sequences & seriesnumber theory | |
| P5 | killer | 0.8 | 5% | 91% | 0.35 | linear algebranumber theory | |
| Day 2 | |||||||
| P6 | medium | 6.1 | 43% | 2% | 0.46 | real analysis | |
| P7 | easy | 7.8 | 73% | 15% | 0.43 | sequences & seriesnumber theory | |
| P8 | very hard | 0.8 | 7% | 91% | 0.38 | combinatorics | |
| P9 | hard | 2.7 | 20% | 62% | 0.60 | linear algebra | |
| P10 | killer | 0.6 | 2% | 89% | 0.36 | probabilitygeometry | |
Field cohort = total ≥ 3 points; difficulty is computed live by the API. Discrimination is the corrected item–total correlation.