Attendance Quizzes, Solutions, and Some Challenges Related to Dr. Z.'s June 30, 2026, DIMACS REU

The Title of the talk was: How to compute Pi by tossing a coin.

Welcome Attendance Quiz (w/o answers)

Dr. Z.'s answers

Best Students' answers

All the posted answers were good, but the lucky winner (of Richard Stanley's book `Catalan Numbers') is Jakub Stepo


Farewell Attendance Quiz (w/o answers)

Best Students' answers

All the posted answers were good, but the lucky winner (of Richard Stanley's book `Catalan Numbers') is John Wu (Princeton University)


Here is the paper (and software) about the

World Cup combinatorics

Challenges: So far my computer (see the above web-page) was only able to find the polynomial describing the number of ways n teams can all play each other and each get r Goals For and r Goals against, for 1 ≤ n ≤ 6. I am pledging to donate 100 dollars to the OEIS in honor of the first person to do it for seven teams, and an additional 200 dollars for eight teams.

Personal Journal of DZ and SBE