0.1 Introduction to Stage 1

What is Stage 1?

Stage 1 is the first test in the Indian National AI Olympiad (INAIO) selection process. It is where you begin with mathematics, logic, and careful reading of unfamiliar problems. Later stages add practical implementation and training. If you want the full picture of how the stages lead to IOAI, read the Introduction to INAIO.

The name of the Olympiad might make you expect a coding test from the start. Stage 1 has asked for answers to objective questions, rather than programs or trained models. The official syllabus begins with mathematical and logical foundations. It also includes basic machine learning ideas and algorithms, but says that questions on those algorithms will provide the background you need. You have to understand that information and reason with it; you do not need to arrive knowing how to implement every algorithm.

For example, a 2025 question described a salt sensor that sometimes gives a false positive. It asked for the probability that the condiment was salt or pepper, given that the sensor said it found salt. You did not need to build the sensor. You needed to read its error rates and use conditional probability. Other questions use classifiers, graphs, or model weights in the same way: the setting may be about AI, while the work is to reason through what the question gives you.

When and where is the test?

The 2025 Stage 1 paper was given online on 25 January 2025, and the 2026 paper was given on 18 January 2026. For INAIO 2027, the organisers have scheduled Stage 1 for 13 December 2026, 10 a.m. to noon, as an in-person test. The official website also says that AI assistants are not allowed for this sitting.

How is the paper organised?

Do not plan around one fixed section layout. The 2025 paper had short problems and longer multi-part problems. The 2026 paper used several A and B sections. In either case, the time limit makes it important to notice how much of the paper you have covered, rather than spending most of your time on one problem.

The cutoff rule can change too. In the 2025 results, one way to qualify was to meet the grade-group cutoffs in both the short and long parts. A sufficiently high score in either part could also qualify through a separate global cutoff. That was the rule for 2025, not a promise about future papers. Read the selection rules published for your own year before deciding how to pace yourself.

Where do you go from here?

The Stage 1 outline in this guide begins with numerical foundations and algebra, then moves through functions, sequences, calculus and optimisation, logic, counting, probability and expected value, geometry, matrices, and graphs. Some of these modules are still being written. For now, the outline shows the path, while the official syllabus and past papers show what actual questions look like.

Next comes Word of Advice. After that, start with the first numbered topic or go directly to a gap you found while trying a past paper.