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        riddles >> medium >> A Chain of 21 Links
        
(Message started by: SAS on Jul 31^st, 2002, 4:03pm)

Title: A Chain of 21 Links
Post by SAS on Jul 31^st, 2002, 4:03pm

What is the least number of links you can cut in a chain of 21 links to be able to give someone all possible number of links up to 21?

Title: Re: New Riddle - Chain 21
Post by Franklinstein on Jul 31^st, 2002, 5:41pm

Does this involve giving change back?

Title: Solution in 3?
Post by srowen on Jul 31^st, 2002, 5:42pm

Cut these links:

OooooooOooooOoooooooo

to get:

o oooooo o oooo o oooooooo

Think of two of the single links together as a "2" and you have an 8, 4, 2 and 1 link chain. That gets all values to 15. The 6 then helps you get anything to 21 also.

Is there an answer in 2?

Title: Re: New Riddle - Chain 21
Post by SAS on Aug 1^st, 2002, 4:29am

Answer to Franklinstein:
Yes, it does involve giving change back.

Answer to srowen:
Yes, there is. ;)

Title: Re: New Riddle - Chain 21
Post by Eric Yeh on Aug 3^rd, 2002, 7:39am

This is not a loop, right? So just cut off two links to leave three pieces of lengths 3, 6, and 10.

It seems to me this is even expandable to 1+1+3+6+12 = 23 link chain, too, no?? What am I missing?

Eric

Title: Re: New Riddle - Chain 21
Post by SAS on Aug 5^th, 2002, 12:02pm

No, it is assumed that we don't have a loop. And your answer is right on target. And you're right about 23, too. To better present the solution I would suggest this:

000 C 000000 C 000000000000

The catch in this riddle is that once you cut a link you can seperate and use it as a single element.

Thanks for checking everybody!

:D

Title: Re: New Riddle - Chain 21
Post by Eric Yeh on Aug 5^th, 2002, 12:08pm

Yup -- thanks for the riddle, SAS. Check out the new ones I posted in the hard section. :)

Looking forward to hearing more of your problems!!

Best,
Eric