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

Home > Logic > Weights and Scales
Four Weights (Posted on 2004-07-25) Difficulty: 3 of 5
You have 4 weights weighing 2,3,5 and 7 pounds. The problem is none of them are marked. What is the fewest number of weighings you need using a balance scale figure out which weights are which?

See The Solution Submitted by Brian Smith    
Rating: 3.5000 (8 votes)

Comments: ( Back to comment list | You must be logged in to post comments.)
re: a computerized start | Comment 4 of 33 |
(In reply to a computerized start by Charlie)

With the useless lines deleted, it's:

            a 2 2 2 2 2 2 3 3 3 3 3 3 5 5 5 5 5 5 7 7 7 7 7 7
            b 3 3 5 5 7 7 2 2 5 5 7 7 2 2 3 3 7 7 2 2 3 3 5 5
            c 5 7 3 7 3 5 5 7 2 7 2 5 3 7 2 7 2 3 3 5 2 5 2 3
            d 7 5 7 3 5 3 7 5 7 2 5 2 7 3 7 2 3 2 5 3 5 2 3 2
ab  v d       \ - - / / / \ - / / / / - / / / / / / / / / / / 18  4  2
ab  v c       - \ / - / / - \ / / / / / - / / / / / / / / / / 18  4  2
ab  v cd      \ \ \ \ / / \ \ \ \ / / \ \ \ \ / / / / / / / / 12  0 12
ac  v d       - / \ / - / / / \ / - / / / - / / / / / / / / / 18  4  2
a   v d       \ \ \ \ \ \ \ \ \ / \ / \ / \ / / / / / / / / / 12  0 12
ad  v c       / - / \ / - / / / \ / - / / / - / / / / / / / / 18  4  2
a   v c       \ \ \ \ \ \ \ \ / \ / \ / \ / \ / / / / / / / / 12  0 12
a   v cd      \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ - - \ \ - - / /  2  4 18
ac  v b       / / - / \ - / / - / \ / / / / / - / / / / / / / 18  4  2
ac  v bd      \ / \ / \ \ \ / \ / \ \ \ / \ / \ \ / / / / / / 12  0 12
ad  v b       / / / - - \ / / / - / \ / / / / / - / / / / / / 18  4  2
a   v b       \ \ \ \ \ \ / / \ \ \ \ / / / / \ \ / / / / / / 12  0 12
a   v bd      \ \ \ \ \ \ \ \ \ \ \ \ \ - \ - \ \ - / \ / \ -  2  4 18
ad  v bc      / \ / \ \ \ / \ / \ \ \ / \ / \ \ \ / / / / / / 12  0 12
a   v bc      \ \ \ \ \ \ \ \ \ \ \ \ - \ - \ \ \ / - / \ - \  2  4 18
bc  v d       / / / / / / - / - / / / \ / \ / / / - / - / / / 18  4  2
b   v d       \ \ \ / / / \ \ \ / / / \ \ \ / / / \ \ \ / / / 12  0 12
bd  v c       / / / / / / / - / - / / / \ / \ / / / - / - / / 18  4  2
b   v c       \ \ / \ / / \ \ / \ / / \ \ / \ / / \ \ / \ / / 12  0 12
b   v cd      \ \ \ \ \ \ \ \ \ \ - - \ \ \ \ / / \ \ \ \ - -  2  4 18
c   v d       \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / 12  0 12

  Posted by Charlie on 2004-07-25 12:06:55
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 (0)
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