perplexus.info :: Weights and Scales : One out of ninety

One out of ninety (Posted on 2013-12-17)

You are presented with a set of 90 coins, appearing identical.
Actually, 89 of them are identical, but one has a different weight.
Using balance scales you have to find the odd coin,
paying $10 each time you use the scales.

What is the maximal (i.e. the worst case) cost to accomplish it?

See The Solution Submitted by Ady TZIDON

Rating: 4.0000 (1 votes)

Comments: ( You must be logged in to post comments.)

Subject	Author	Date
One out of 121 !!	Steve Herman	2015-12-19 19:20:20
re: One out of One Hundred Twenty!	Steve Herman	2015-12-18 20:18:01
One out of One Hundred Twenty!	Brian Smith	2015-12-18 00:03:15
One out of 121?	Steve Herman	2013-12-18 22:34:02
One out of 92! (spoiler)	Steve Herman	2013-12-18 12:58:52
Minimum of the minimum of the maximum	Steve Herman	2013-12-17 16:27:22
Where there's a will, there's a weigh (spoiler?)	Steve Herman	2013-12-17 16:02:36

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:


perplexus dot info