The A105 Problem of the Fortnight

This is the official website of the A105 Problem of the Fortnight. The problem will be located to the right of our door on the small white board and I will try to post it online here each time I update it, which will hopefully be about each fortnight.

4:36 PM 12/21/2006: I just added the solution to the November 26 problem. The A105 POTF (or whatever it ends up being called) will not resume until next quarter.

4:10 PM 12/21/2006: The solution to the November 12 problem is finally up. The November 26 solutions will be up by the end of the day. I've also made a few relatively minor changes to the site.

4:06 PM 11/29/2006: There has been a new problem on the white board since Sunday. It has now been posted online. The solution to the November 12 problem will go up sometime soon. Wait for further announcements.

3:45 AM 11/18/2006: Sorry it's late, but there is a new problem. Hopefully I'll have the solution up by the end of the break.

6:43 PM 11/11/2006: So I've changed a few things around on the site and about the problems. I've decided to just give up on failing to get a problem up each week and just follow the trend so far of a new problem every two weeks. Hence, I have renamed the A105 Problem of the Week to the A105 Problem of the Fortnight. I've also changed the order of the recent updates so that the newest are on top. Oh, and look for a new problem to show up here sometime tomorrow. With the new setup, I will post a problem on one weekend and then its solution the following weekend and then the next problem will be posted the weekend after that.

9:00 PM 11/5/2006: The solution to this past week's POTW is up. There will not be a POTW for this week unless I get demand for it. The hardest thing is to think of or come across good problems. Suggestions are always welcome. Of course, if there is sufficient demand, I may put up a problem for this week. If people are alright for me to continue with the proofs, I have one in mind that some could find interesting and that has a nice argument for its proof. Let me know.

1:12 AM 10/29/2006: POTW for the week of October 29th is up. See either the link below or the whiteboard next to our door. The solution will only be posted online this week since it is a proof.

11:39 PM 10/27/2006: Expect to see a new problem on the white board on Sunday. It will be posted online on Sunday as well because I already have the electronic version written up.

• POTF for October 15, 2006 (35 KiB)
• POTF for October 29, 2006 (35 KiB)
• POTF for November 12, 2006 (31 KiB)
• POTF for November 26, 2006 (33 KiB)

And, as each fortnight passes, I will post the solutions to the problems below:

• Solution to POTF for October 15, 2006 (40 KiB)
• Solution to POTF for October 29, 2006 (43 KiB)
• Solution to POTF for November 12, 2006 (42 KiB)
• Solution to POTF for November 26, 2006 (35 KiB)

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Last Modified:  6:35 PM 12/21/2006