All about flooble | fun stuff | Get a free chatterbox | Free JavaScript | Avatars    
perplexus dot info

Home > Just Math
Dates data distribution (Posted on 2015-01-05) Difficulty: 3 of 5
Consider all possible dates (formatted DD/MM/YY) within a span of a century , from 01/01/01 to 31/12/00 (20th century!).
In this period there are N k dates that can be expressed by k distinct digits, e.g. N1=1 (11/11/11).

a. Derive the values of N k for all other values of k (2 to 6).
b. What is the average k for the 20st century?
c. How about the 21st century?

No Solution Yet Submitted by Ady TZIDON    
No Rating

Comments: ( Back to comment list | You must be logged in to post comments.)
Hints/Tips re: computer-aided solution | Comment 2 of 3 |
(In reply to computer-aided solution by Charlie)

Charlie,

Each of us committed an error, and it slightly affects your otherwise

perfect solution:

a. I wrongly defined the 20 th century, shifting it forward a year.

b. You wrongly assumed that 2100 is a leap year, and it is not.

I would appreciate it  if you modify your entry.

Thanks.


  Posted by Ady TZIDON on 2015-01-05 17:55:54
Please log in:
Login:
Password:
Remember me:
Sign up! | Forgot password


Search:
Search body:
Forums (0)
Newest Problems
Random Problem
FAQ | About This Site
Site Statistics
New Comments (1)
Unsolved Problems
Top Rated Problems
This month's top
Most Commented On

Chatterbox:
Copyright © 2002 - 2017 by Animus Pactum Consulting. All rights reserved. Privacy Information