Problem of the Week

How many integers $m$ and $n$ are there such that $m+n=mn$?

Due Wednesday, March 29 at midnight submitted to this Google form. You must be logged into your NAU gmail to submit via this form. If you are having trouble with the form, feel free to email a solution to

Rules for Problem of the Week

The contest is open to all undergraduates at Northern Arizona University. Solutions are due at midnight of every Wednesday.

Submit your solutions to this Google form as a pdf or jpg of either typed or neatly handwritten and scanned work. If you don't have access to a scanner use a phone app like CamScanner or Adobe Scan.

**The answers should be clearly and logically explained. ** The goal is to write mathematics, not to to write down the answer and draw a box around it.

Send your questions to Rachel Neville at If your instructor gives you credit for submissions to problem of the week, please include their name and the class in the form (e.g. Swift, MAT 239) the first time you submit a solution. (After that I have the information in my spreadsheet.)

Problems will be graded on a scale of 1 to 3. A model solution is posted each week. A ladder listing the points earned is posted in the lobby of the Adel Math Building (across from the MAP room). Your name will be printed on the ladder, but no names will be published on the web. Let me know if you want to remain anonymous on the posted ladder and what name you would prefer to use.