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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    
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Hints/Tips re: computer-aided solution | Comment 2 of 3 |
(In reply to computer-aided solution by 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.


  Posted by Ady TZIDON on 2015-01-05 17:55:54
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