a! * b! = c!
Find three numbers where a is less than b and b is less than c
where a! * b! = c!
where a! * b! = c!
Labels: mathemagic
posted by Ragknot at
10:18 PM
Friday, October 23, 2009
Links
Search
Share
- Tom Chrome Extension
- ToM @ Twitter
- MeeT ToM
- Daily Tricks Widget
- Vista Gadget 1.5
- iPhone Widget
- Windows XP Widget
- Google Toolbar Button
- Suggestions
Favorite Links
- Vista Sidebar Gadgets
- Widgets for Web 2.0
- C Sharp Tricks
- Interview Information
- Illustrator - Elar Alexander
Bookmark Us
Previous Posts
- Super Women
- 1997 was a PRIME year
- Ordered Pairs
- Urgent Letter
- Duelling dilemma
- 1-9 again
- 1 to 9
- soaking it up
- dicey die
- flipping furniture
4 Comments:
3! * 5! = 6!
There are probably infinite solutions, but I'm pretty sure that's the smallest one. Another I found was 6! * 7! = 10!
Yes, there are an infinite number of solutions. One class of solutions can be generated from:
a! * (a!-1)! = a!! for all integral values of a >= 3. Thus:
3! * (3!-1)! = 3!!, i.e. 3! * 5! = 6!.
Similarly,
4! * 23! = 24!
5! * 119! = 120!
6! * 719! = 720!
etc, etc.
Very good guys.
And Wiz, I checked those and saw they were correct. How did you figure 719! and 720! - I used my BigNum libary to get them.
Hi Ragnot,
No Bignum library needed here.
6! = 720, so obviously 720 * 719! = 720!
Post a Comment
Links to this post:
Create a Link
<< Home