Problems

Here are the problems and solutions of previous years’ PION.

• 2023: Problems and Answers
• 2020: Problems and Answers
• 2019: Problems and Answers
• 2018: Problems and Answers
• 2016: Problems and Answers
• 2015: Problems and Answers
• 2014: Problems and Answers
• 2013: Problems and Answers
• 2012: Problems and Answers