# Pi Mu Epsilon Undergraduate Math Society at USC Fall 2005 Semester

## September 19.

The Putnam exam this year is Saturday, Dec. 3 9 am-12noon (A session), then lunch, then 1-4pm (B session), more or less,

Prof. Lototsky prepared a handout, 7 2-sided sheets, giving 14 years worth of Putnam problems, 1991-2004.

For next week, we hope to get some written solutions for (strict, Putnam-style) grading. The problems will be A1,A2,B1, and B2, from 1991 and 1992. People took individual problems as "assigned" --- after trying to solve it, look up solutions on the web, and be prepared to present a solution to the meeting. The matching was 1991 A1 Sunny, A2 Mark, B1 Kelly, B2 Daniel 1992 A1 Alex, A2 Timothy, B1 Colin, B2 Alex.

## September 26.

One new person attended:
Angela Stirm (junior) stirm@usc.edu
Alex, Mark, Timothy, Colin, and Sunny each presented one solution. Some solutions were perfect, some others needed more. But, overall, this seems like a good procedure, and I hope we repeat it. Unfortunately, we only thought of next week --- Oct 3, as time was running out. So rather than the ideal of making individual assignments, we simply ask that everyone try (some) of 1993 A1-2, B1-2. As always, feel invited both to find your own solution, and to find solutions on the web. Presenting even the latter is valuable training.

## October 3.

There were four students and two profs. What a ratio! Alex, Colin, Tim, and Sunny each presented one of 1993 A1-2,B1-2. We have individual assignments for next week: the 1994 exam, Alex A1, Colin A2, Tim B1, Sunny B2.

On 1993 B2, we needed a better proof that B always wins. Here is a proof by Professor Arratia:

## October 10.

In attendance were Profs. Arratia and Lototsky, grad student/puzzle guru Igor Cialenco, and undergrads Angela, Collin, and Sunny. We looked at problems 1995 A1, 1994 A2, and 1994 B2. We also talked about pigeon-hole pronciple and tried 1994 A3.

## October 17.

In attendance were Prof. Arratia, grad student Igor Cialenco, and undergrads Alex and Timothy. We looked at problems 1995 B2, A1, 1994 A1, and 1991 B2.

Suggested focus for October 24: (1995 A2, B1) and (1996 the usual 4, i.e. A1, A2, B1, B2).

## October 24.

On Oct 24, we met with 6 students, 2 professors, 1 grad student. We looked at 1995 B3, ( 1995 B4 with only partial result), (1996 B1 and B2).

We signed up individual volunteers for next week: Angela 96 A2 and or 97 B1 Mark 97 A3 Alex 96 B3 Jeff Pennington 97 A4 Michael Johnson 97 A5