HP Forums
OT - date digit challenge - Printable Version

+- HP Forums (https://archived.hpcalc.org/museumforum)
+-- Forum: HP Museum Forums (https://archived.hpcalc.org/museumforum/forum-1.html)
+--- Forum: Old HP Forum Archives (https://archived.hpcalc.org/museumforum/forum-2.html)
+--- Thread: OT - date digit challenge (/thread-90678.html)



OT - date digit challenge - Don Shepherd - 04-06-2006

OK guys, something light.

Yesterday it was 01:23:45 6/7/89. Big deal. I liked 01:23:45 6/7/89 better anyhow.

Now, for the challenge. What was the last date that had all odd number digits? When will the next date be with all odd digits?


Re: OT - date digit challenge - bill platt - 04-06-2006

November 29, 2005
January 1, 2007


Re: OT - date digit challenge - Don Shepherd - 04-06-2006

Hey Bill, that's right if you only consider the 2 digit year. What if you consider the 4 digit year?


Re: OT - date digit challenge - bill platt - 04-06-2006

There's no difference. Odd numbers are a function of the last digit.

Or do you want all *digits* to be odd?

In that case, you hav to go back to Nov 29, 1999 and forward to Jan 1, 3111!


Re: OT - date digit challenge - Don Shepherd - 04-06-2006

Yes, you are right, I didn't explain it well enough. I wanted all digits to be odd.

Nov 19, 1999




Re: OT - date digit challenge - bill platt - 04-06-2006

oh, roight. sorry.

Now, same problem as before, except that if you add up all the digits, the sum must also be odd. (both of these answers are even).

Edited: 6 Apr 2006, 12:13 p.m.


Re: OT - date digit challenge - Don Shepherd - 04-06-2006

Bill, you're a crafty guy!

11/9/1999

1/11/3111

Neither of which has ANYTHING to do with my teaching portfolio, which I'm supposed to be working on today.