Rules & scoring
NC(J)MO follows a BAMO-style proof-based format.
Contest format
| Problems | 5 proof problems |
|---|---|
| Time limit | 3 hours |
| Per problem | Up to 7 points |
| Total | Up to 35 points |
Scoring
Solutions are graded on completeness, clarity, and correctness. A complete solution includes the reasoning that proves your answer.
Useful progress can earn partial credit. Submit the work you have, even if you have not fully solved a problem.
Permitted materials
The published contest instructions permit only writing utensils, erasers, and an optional straightedge and compass as tools.
Writing and submitting solutions
- Explain your reasoning clearly, with enough detail to justify your conclusions.
- When a problem asks for the greatest or least possible value, give an example that achieves your answer and prove that no better value is possible.
- Label each page as your contest paper instructs. The 2025 papers ask for your contestant ID, problem number, and solution page number in the top right corner of every page you submit.
These format, scoring, and page-labeling instructions are published in the 2025 NCJMO paper and 2025 NCMO paper.
About NC(J)MO
The North Carolina (Junior) Math Olympiad is a proof-based math competition. Through NCJMO and NCMO, students with a range of experience can work on challenging problems and write complete mathematical arguments.
Our mission is to make proof-based olympiads accessible to the community. We encourage students who are new to proof writing to participate, while offering difficult problems that challenge experienced contestants.
Contest divisions
Compare the guidance below and explore past problems to find the appropriate difficulty.
NCJMO
Recommended for students beginning to explore math beyond school or the AMCs, including those who are new to proof writing.
The difficulty is similar to BAMO-8. Explore past NCJMO problems to see what to expect.
NCMO
Recommended for students who have comfortably qualified for the AIME or have experience with proof writing, such as from an advanced math course.
The difficulty is approximately USAJMO level, with a couple of easier problems at the beginning and potentially a particularly challenging one at the end.
Common questions
Proofs seem hard! Should I take the NC(J)MO?
First things first, don’t be intimidated by the word “proof”! Think of it as a fancy way of saying, “explain your thought process as clearly as you can.” We encourage you to take the NC(J)MO even if you’re inexperienced!
Does NC(J)MO have the same difficulty as USA(J)MO?
NCJMO is similar in difficulty to BAMO-8. NCMO is approximately USAJMO level, with a couple of easier problems at the beginning and potentially a particularly challenging one at the end.