perplexus.info :: Numbers : How many 1s?

How many 1s? (Posted on 2004-07-26)

If I took all the numbers from one to one billion:

How many of them contain at least one '1'?
If I wrote them out in one long line, how many 1 digits would there be?

Submitted by Thalamus

Rating: 3.0000 (12 votes)

Solution: (Hide)

I don't think I could state it any better than Federico did in his solution.
His calculations come up to 612,579,512 for question 1, and 900,000,001 for question 2.

Comments: ( You must be logged in to post comments.)

Subject	Author	Date
Problem Solution	K Sengupta	2007-05-04 13:20:00
201987512 ::shrugs::	nathan	2004-09-14 14:50:24
re: Hey, you, get offa my cloud (Solution)	nathan	2004-09-14 14:49:42
Solution?	terri	2004-08-21 22:27:19
Scratch the Last- Maybe Both	Eric	2004-08-07 23:13:28
Solution???	Eric	2004-08-07 23:06:33
soln	neshal	2004-08-02 07:05:52
Wrong answer	Dustin Smith	2004-07-31 08:29:43
re: Possible Solution	Penny	2004-07-31 07:19:12
Possible Solution	Dustin Smith	2004-07-31 02:28:56
re: The solution??	saddi Sandy	2004-07-30 08:01:03
The solution??	Vee-Liem Veefessional	2004-07-30 02:14:20
re(2): Solutions	Charlie	2004-07-26 10:54:50
re: Solutions	Charlie	2004-07-26 10:50:27
Hey, you, get offa my cloud (Solution)	Penny	2004-07-26 10:10:26
Solutions	Federico Kereki	2004-07-26 07:56:54

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