Putnam Exam 2019, Problem A1
Putnam Exam 2019, Problem A2
Putnam Exam 2019, Problem A4
Putnam Exam 2018, Problem A1
Putnam Exam 2017, Problem A1
Putnam Exam 2017, Problem A2
Putnam Exam 2017, Problem A3
Putnam Exam 2017, Problem A4
Putnam Exam 2017, Problem A5
Putnam Exam 2017, Problem A5 optional Appendix.
Putnam Exam 2017, Problem A6
Putnam Exam 2017, Problem B3
Putnam Exam 2017, Problem B4