perplexus.info :: Numbers : Prime Time

Prime Time (Posted on 2002-12-17)

There are 362,880 different numbers that use the digits 1 to 9 exactly once (like 187,432,569).

Of these, what percentage are prime numbers?

Submitted by cges

Rating: 3.1538 (13 votes)

Solution: (Hide)

An old problem
Please see the solutions in the comments.
My solution below is short and sweet, but some of the others given are well thought out and appreciated.
The answer is - 0%. All those numbers add up to 45 or 5 * 9. All are divisible by 9.

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

Subject	Author	Date
Thoughts On A Possible Extension	K Sengupta	2008-02-26 23:36:54
Puzzle Solution	K Sengupta	2008-02-26 22:31:03
re(3): German solution	Hugo	2005-12-30 02:40:22
re(2): German solution	MindRod	2005-12-29 21:55:16
re: German solution	Hugo	2005-12-29 03:32:38
German solution	MindRod	2005-12-29 00:00:29
easy	ethan	2003-05-08 10:51:19
re(2): simple guess	Gamer	2003-04-26 12:16:42
re: simple guess	TomM	2002-12-17 03:31:00
simple guess	Nick Murray	2002-12-17 02:57:24

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 (3)
Unsolved Problems
Top Rated Problems
This month's top
Most Commented On

Chatterbox:


perplexus dot info