Mark Sellke

In middle and high school I participated in many math competitions. At the pre-olympiad level I recommend Art of Problem Solving's Counting and Probability series. At the olympiad level I recommend Problems from the Book.

Some teaching experiences:

• During summers 2015, 2017, 2018, and 2021 I was an instructor at the Math Olympiad Program.
• In 2016 I cofounded Contest Math Tutoring.
• In 2018 I coached Brazil's IMO team for one week in Sao Paulo.
• In summer 2021 I coached Ghana's IMO team via the MISE Foundation.

Olympiad problems I contributed USA team selection tests, in increasing difficulty order:

• TSTST 2015 #4
• December TST 2015 #3
• January TST 2018 #3

Math olympiad handouts:

• Farey Sequences
• Convex Geometry
• Gauss Sums
• Random Walks

Other favorite olympiad problems:

• Olympiad Problems

Here are some of my own math competition results.

• First place on 2014 Putnam Exam.
• Gold medalist at 2013, 2014 International Math Olympiads.
• Top 12 winner of 2011, 2013, 2014 USA Math Olympiads.
• National Champion of 2010 MathCounts.