You will be required to write a complete book on the theory required for IMO. There's plenty of literature on the topic, so search on the net for further information. In order to apply for the job, you have to submit one sample chapter of the book, that you can use elsewhere if not chosen, Otherwise, if chosen, you will start the work and add that chapter to the others.
For the sample choose one topic among:
Each chapter of the book has to contain theory and some examples, not questions.
Ask for further explanations.
7 days time to submit the sample. Write AGREE at the top of the bid, so that I will see if you've read the conditions.