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

Home > General
Building a ruler (Posted on 2008-11-14) Difficulty: 2 of 5
I have an unmarked ruler (AD) of length 6cm. Making two marks in it, one (B) at 1cm from the left end and other (C) at 2cm from the right end, Im able to measure any integer length from 1 to 6 cm:
       +----+-------------+--------+
       A    B             C        D
AB = 1cm / CD = 2cm / BC = 3cm / AC = 4cm / BD = 5cm / AD = 6cm.

If I have an unmarked ruler of length 14cm, what is the minimum number of marks, and where do I have to make them, in order to be able to measure any integer length from 1 to 14cm?

See The Solution Submitted by pcbouhid    
No Rating

Comments: ( Back to comment list | You must be logged in to post comments.)
re: Catch? | Comment 3 of 10 |
(In reply to Catch? by ed bottemiller)

As you pointed out it's easy to see there's more than one solution, thus rather than focusing on "the" solution, a solver might provide one such solution.

However, I think the main point is to prove you can't do it with 4 or fewer marks, since there's theoretically 15 distances. (Also keep in mind this is D2, so it's unlikely the solution is anything difficult)

  Posted by Gamer on 2008-11-14 18:33:08

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