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

Home > Just Math
Sum Inverse LCMs (Posted on 2008-10-03) Difficulty: 3 of 5
Each of P, Q, R, S and T are positive integers with P < Q < R < S < T. Determine the maximum value of the following expression.

[P, Q] -1 + [Q, R] -1 + [R, S] -1 + [S, T] -1

Note: [x, y] represents the LCM of x and y.

No Solution Yet Submitted by K Sengupta    
Rating: 3.5000 (2 votes)

Comments: ( Back to comment list | You must be logged in to post comments.)
re: Extension (and ideas) Comment 7 of 7 |
(In reply to Extension (and ideas) by Gamer)

I agree completely with Gamer's points:

a) a series of any length would be more interesting
b) switching any term of 1,2,4,8,16 ... to a larger number results in a smaller result, and doesn't work.
c) We still need to prove that switching a term of 1,2,4,8,16 ... to a small number also results in a smaller result.  This hasn't been done yet.
  Posted by Steve Herman on 2008-10-05 11:05:39

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