Department of Mathematics

Problem of the Week

Current Problem

Download current problem as Adobe Acrobat document

About the Problem of the Week...

A panel in the Mathematics Department publishes a challenging problem once a week and invites college & pre-college students, faculty, and staff to submit solutions. The objective of this is to stimulate and cultivate interest in good mathematics, especially among younger students. Solutions are due within two weeks from the date of publication and should be sent by campus or U.S. Postal mail to:

Problem of the Week
Department of Mathematics, Purdue University
150 N. University Street, West Lafayette, IN 47907-2067

Solutions may also be emailed as a pdf attachment to Shu-fang Chang or faxed to 765-496-3177.

Questions and concerns about Problem of the Week can be directed to Shu-fang Chang.

Every Purdue student who submits three or more correct solutions will receive a Certificate of Merit. Each semester, a prize fund of $300.00 will be distributed among the Purdue undergraduates who have contributed at least six correct solutions for that semester series.

About the founder of Problem of the Week

Michael Golomb, who passed away on April 9, 2008 at the age of 98, began the Problem of the Week program and ran it for many years. A few years ago, health problems forced him to stop administering the program, but he continued to provide the problems. And even now many of the problems appearing in Problem of the Week were provided by Michael Golomb. He created many of the problems himself, and collected (and often modified) the others from various sources.

For more information see Michael Golomb's obituary.

Problem History:

Semester Problem Solution
Spring 2013      Problem 13      Solution 13     
     Problem 12      Solution 12     
     Problem 11      Solution 11     
     Problem 10      Solution 10     
     Problem 9      Solution 9     
     Problem 8      Solution 8     
     Problem 7      Solution 7     
     Problem 6      Solution 6     
     Problem 5      Solution 5     
     Problem 4      Solution 4     
     Problem 3      Solution 3     
     Problem 2      Solution 2     
     Problem 1      Solution 1     
Fall 2012      Problem 13      Solution 13     
     Problem 12      Solution 12     
     Problem 11      Solution 11     
     Problem 10      Solution 10     
     Problem 9      Solution 9     
     Problem 8      Solution 8     
     Problem 7      Solution 7     
     Problem 6      Solution 6     
     Problem 5      Solution 5     
     Problem 4      Solution 4     
     Problem 3      Solution 3     
     Problem 2      Solution 2     
     Problem 1      Solution 1     
Spring 2012      Problem 14      Solution 14     
     Problem 13      Solution 13     
     Problem 12      Solution 12     
     Problem 11      Solution 11     
     Problem 10      Solution 10     
     Problem 9      Solution 9     
     Problem 8      Solution 8     
     Problem 7      Solution 7     
     Problem 6      Solution 6     
     Problem 5      Solution 5     
     Problem 4      Solution 4     
     Problem 3      Solution 3     
     Problem 2      Solution 2     
     Problem 1      Solution 1     
Fall 2011      Problem 14      Solution 14     
     Problem 13      Solution 13     
     Problem 12      Solution 12     
     Problem 11      Solution 11     
     Problem 10      Solution 10     
     Problem 9      Solution 9     
     Problem 8      Solution 8     
     Problem 7      Solution 7     
     Problem 6      Solution 6     
     Problem 5      Solution 5     
     Problem 4      Solution 4     
     Problem 3      Solution 3     
     Problem 2      Solution 2     
     Problem 1      Solution 1     
Spring 2011      Problem 14      Solution 14     
     Problem 13      Solution 13     
     Problem 12      Solution 12     
     Problem 11      Solution 11     
     Problem 10      Solution 10     
     Problem 9      Solution 9     
     Problem 8      Solution 8     
     Problem 7      Solution 7     
     Problem 6      Solution 6     
     Problem 5      Solution 5     
     Problem 4      Solution 4     
     Problem 3      Solution 3     
     Problem 2      Solution 2     
     Problem 1      Solution 1     
Fall 2010      Problem 14      Solution 14     
     Problem 13      Solution 13     
     Problem 12      Solution 12      * revised
     Problem 11      Solution 11     
     Problem 10      Solution 10     
     Problem 9      Solution 9     
     Problem 8      Solution 8     
     Problem 7      Solution 7     
     Problem 6      Solution 6     
     Problem 5      Solution 5     
     Problem 4      Solution 4     
     Problem 3      Solution 3     
     Problem 2      Solution 2     
     Problem 1      Solution 1     
Spring 2010      Problem 14      Solution 14     
     Problem 13      Solution 13     
     Problem 12      Solution 12     
     Problem 11      Solution 11     
     Problem 10      Solution 10     
     Problem 9      Solution 9     
     Problem 8      Solution 8     
     Problem 7      Solution 7     
     Problem 6      Solution 6     
     Problem 5      Solution 5     
     Problem 4      Solution 4     
     Problem 3      Solution 3     
     Problem 2      Solution 2     
     Problem 1      Solution 1     
Fall 2009      Problem 14      Solution 14     
     Problem 13      Solution 13     
     Problem 12      Solution 12     
     Problem 11      Solution 11     
     Problem 10      Solution 10     
     Problem 9      Solution 9     
     Problem 8      Solution 8     
     Problem 7      Solution 7     
     Problem 6      Solution 6      * revised
     Problem 5      Solution 5      * revised
     Problem 4      Solution 4      * revised
     Problem 3      Solution 3      * revised
     Problem 2      Solution 2     
     Problem 1      Solution 1     
Spring 2009      Problem 14      Solution 14     
     Problem 13      Solution 13     
     Problem 12      Solution 12     
     Problem 11      Solution 11     
     Problem 10      Solution 10     
     Problem 9      Solution 9     
     Problem 8      Solution 8     
     Problem 7      Solution 7     
     Problem 6      Solution 6     
     Problem 5      Solution 5     
     Problem 4      Solution 4     
     Problem 3      Solution 3     
     Problem 2      Solution 2     
     Problem 1      Solution 1     
Fall 2008      Problem 14      Solution 14     
     Problem 13      Solution 13     
     Problem 12      Solution 12     
     Problem 11      Solution 11     
     Problem 10      Solution 10     
     Problem 9      Solution 9     
     Problem 8      Solution 8     
     Problem 7      Solution 7     
     Problem 6      Solution 6     
     Problem 5      Solution 5     
     Problem 4      Solution 4     
     Problem 3      Solution 3     
     Problem 2      Solution 2     
     Problem 1      Solution 1     
Spring 2008      Problem 14      Solution 14     
     Problem 13      Solution 13     
     Problem 12      Solution 12     
     Problem 11      Solution 11     
     Problem 10      Solution 10     
     Problem 9      Solution 9     
     Problem 8      Solution 8     
     Problem 7      Solution 7     
     Problem 6      Solution 6     
     Problem 5      Solution 5     
     Problem 4      Solution 4     
     Problem 3      Solution 3     
     Problem 2      Solution 2     
     Problem 1      Solution 1     
Fall 2007      Problem 14      Solution 14     
     Problem 13      Solution 13     
     Problem 12      Solution 12     
     Problem 11      Solution 11     
     Problem 10      Solution 10     
     Problem 9      Solution 9     
     Problem 8      Solution 8     
     Problem 7      Solution 7     
     Problem 6      Solution 6     
     Problem 5      Solution 5     
     Problem 4      Solution 4     
     Problem 3      Solution 3     
     Problem 2      Solution 2     
     Problem 1      Solution 1     
Spring 2007      Problem 14      Solution 14     
     Problem 13      Solution 13     
     Problem 12      Solution 12     
     Problem 11      Solution 11     
     Problem 10      Solution 10     
     Problem 9      Solution 9     
     Problem 8      Solution 8     
     Problem 7      Solution 7     
     Problem 6      Solution 6     
     Problem 5      Solution 5      * revised
     Problem 4      Solution 4      * revised
     Problem 3      Solution 3     
     Problem 2      Solution 2     
     Problem 1      Solution 1     
Fall 2006      Problem 14      Solution 14     
     Problem 13      Solution 13     
     Problem 12      Solution 12     
     Problem 11      Solution 11     
     Problem 10      Solution 10     
     Problem 9      Solution 9     
     Problem 8      Solution 8     
     Problem 7      Solution 7     
     Problem 6      Solution 6     
     Problem 5      Solution 5     
     Problem 4      Solution 4     
     Problem 3      Solution 3     
     Problem 2      Solution 2     
     Problem 1      Solution 1     
Spring 2006      Problem 14      Solution 14     
     Problem 13      Solution 13     
     Problem 12      Solution 12     
     Problem 11      Solution 11     
     Problem 10      Solution 10     
     Problem 9      Solution 9     
     Problem 8      Solution 8     
     Problem 7      Solution 7     
     Problem 6      Solution 6     
     Problem 5      Solution 5     
     Problem 4      Solution 4     
     Problem 3      Solution 3     
     Problem 2      Solution 2     
     Problem 1      Solution 1     
Fall 2005      Problem 14      Solution 14     
     Problem 13      Solution 13     
     Problem 12      Solution 12     
     Problem 11      Solution 11     
     Problem 10      Solution 10     
     Problem 9      Solution 9     
     Problem 8      Solution 8     
     Problem 7      Solution 7     
     Problem 6      Solution 6     
     Problem 5      Solution 5     
     Problem 4      Solution 4     
     Problem 3      Solution 3     
     Problem 2      Solution 2     
     Problem 1      Solution 1     
Spring 2005      Problem 14      Solution 14     
     Problem 13      Solution 13     
     Problem 12      Solution 12     
     Problem 11      Solution 11     
     Problem 10      Solution 10     
     Problem 9      Solution 9     
     Problem 8      Solution 8     
     Problem 7      Solution 7     
     Problem 6      Solution 6     
     Problem 5      Solution 5     
     Problem 4      Solution 4     
     Problem 3      Solution 3     
     Problem 2      Solution 2     
     Problem 1      Solution 1     
Fall 2004      Problem 14      Solution 14     
     Problem 13      Solution 13     
     Problem 12      Solution 12     
     Problem 11      Solution 11     
     Problem 10      Solution 10     
     Problem 9      Solution 9     
     Problem 8      Solution 8     
     Problem 7      Solution 7     
     Problem 6      Solution 6     
     Problem 5      Solution 5     
     Problem 4      Solution 4     
     Problem 3      Solution 3     
     Problem 2      Solution 2     
     Problem 1      Solution 1     
Spring 2004      Problem 14      Solution 14     
     Problem 13      Solution 13     
     Problem 12      Solution 12     
     Problem 10      Solution 10     
     Problem 9      Solution 9     
     Problem 8      Solution 8     
     Problem 7      Solution 7     
     Problem 6      Solution 6     
     Problem 5      Solution 5     
     Problem 4      Solution 4     
     Problem 3      Solution 3     
     Problem 2      Solution 2     
     Problem 1      Solution 1     
Fall 2003      Problem 14      Solution 14     
     Problem 13      Solution 13     
     Problem 12      Solution 12     
     Problem 11      Solution 11     
     Problem 10      Solution 10     
     Problem 9      Solution 9     
     Problem 8      Solution 8     
     Problem 7      Solution 7     
     Problem 6      Solution 6     
     Problem 5      Solution 5     
     Problem 4      Solution 4     
     Problem 3      Solution 3     
     Problem 2      Solution 2     
     Problem 1      Solution 1     
Spring 2003      Problem 14      Solution 14     
     Problem 13      Solution 13     
     Problem 12      Solution 12     
     Problem 11      Solution 11     
     Problem 10      Solution 10     
     Problem 9      Solution 9     
     Problem 8      Solution 8     
     Problem 7      Solution 7     
     Problem 6      Solution 6     
     Problem 5      Solution 5     
     Problem 4      Solution 4     
     Problem 3      Solution 3     
     Problem 2      Solution 2     
     Problem 1      Solution 1     
Fall 2002      Problem 13      Solution 13     
     Problem 12      Solution 12     
     Problem 11      Solution 11     
     Problem 10      Solution 10     
     Problem 9      Solution 9     
     Problem 8      Solution 8     
     Problem 7      Solution 7     
     Problem 6      Solution 6     
     Problem 5      Solution 5     
     Problem 4      Solution 4     
     Problem 3      Solution 3     
     Problem 2      Solution 2     
     Problem 1      Solution 1     
Spring 2002      Problem 14      Solution 14     
     Problem 13      Solution 13     
     Problem 12      Solution 12     
     Problem 11      Solution 11     
     Problem 10      Solution 10     
     Problem 9      Solution 9     
     Problem 8      Solution 8     
     Problem 7      Solution 7     
     Problem 6      Solution 6     
     Problem 5      Solution 5     
     Problem 4      Solution 4     
     Problem 3      Solution 3     
     Problem 2      Solution 2     
     Problem 1      Solution 1     
Fall 2001      Problem 14      Solution 14     
     Problem 13      Solution 13     
     Problem 12      Solution 12     
     Problem 11      Solution 11     
     Problem 10      Solution 10     
     Problem 9      Solution 9     
     Problem 8      Solution 8     
     Problem 7      Solution 7     
     Problem 6      Solution 6     
     Problem 5      Solution 5     
     Problem 4      Solution 4     
     Problem 3      Solution 3     
     Problem 2      Solution 2     
     Problem 1      Solution 1     
Spring 2001      Problem 14      Solution 14     
     Problem 13      Solution 13     
     Problem 12      Solution 12     
     Problem 11      Solution 11     
     Problem 10      Solution 10     
     Problem 9      Solution 9     
     Problem 8      Solution 8     
     Problem 7      Solution 7     
     Problem 6      Solution 6     
     Problem 5      Solution 5     
     Problem 4      Solution 4     
     Problem 3      Solution 3     
     Problem 2      Solution 2     
     Problem 1      Solution 1     
Fall 2000      Problem 14      Solution 14     
     Problem 13      Solution 13     
     Problem 12      Solution 12     
     Problem 11      Solution 11     
     Problem 10      Solution 10     
     Problem 9      Solution 9     
     Problem 8      Solution 8     
     Problem 7      Solution 7     
     Problem 6      Solution 6     
     Problem 5      Solution 5     
     Problem 4      Solution 4     
     Problem 2      Solution 2     
     Problem 1      Solution 1