perplexus.info :: Weights and Scales : Radioactive Coins

Radioactive Coins (Posted on 2006-10-17)

You have N coins, 2 of which are radioactive. You have a radioactivity detector which can test any subset of the coins at a time, and return the number of radioactive coins in the group (i.e. it returns 0, 1 or 2). You have to find the radioactive coins, using not more than 10 tests. What is the largest N for which this is possible?

No Solution Yet Submitted by David Shin

Rating: 4.5000 (6 votes)

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

Subject	Author	Date
Puzzle Solution	K Sengupta	2024-01-02 02:30:42
Puzzle Thoughts	K Sengupta	2023-07-28 12:28:51
re(4): Fibonacci Connection.....placed	Ady TZIDON	2016-02-16 07:16:35
re(3): Fibonacci Connection.....placed	Brian Smith	2016-02-15 23:10:12
re(2): Fibonacci Connection.....placed	Ady TZIDON	2016-02-14 19:19:18
re: Fibonacci Connection	Brian Smith	2016-02-14 12:00:22
Fibonacci Connection	Brian Smith	2016-02-10 12:11:57
Generalisation	FrankM	2008-02-03 11:20:29
Worst case answer	Tyryt	2007-08-14 17:38:02
An algorithm for potentially determining exact solution	gregg	2006-10-24 23:04:56
A little bit closer	Joel	2006-10-20 17:48:05
re(2): New high - Marvelous	Joel	2006-10-20 13:24:22
a scenario that always works	Cyriis	2006-10-20 13:13:34
re: New high - Marvelous	Leming	2006-10-19 15:50:48
New high	Joel	2006-10-19 12:14:51
Not opimum: 48	Jer	2006-10-19 11:44:36
re: A better solution	Leming	2006-10-18 15:43:46
A better solution	Joel	2006-10-17 22:32:55
information theory vs. practicalities	Charlie	2006-10-17 15:25:05
thoughts	siddhesh	2006-10-17 14:47:51

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