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Radioactive Coins (Posted on 2006-10-17) Difficulty: 5 of 5
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
re(4): Fibonacci Connection.....placedAdy TZIDON2016-02-16 07:16:35
re(3): Fibonacci Connection.....placedBrian Smith2016-02-15 23:10:12
Hints/Tipsre(2): Fibonacci Connection.....placedAdy TZIDON2016-02-14 19:19:18
Some Thoughtsre: Fibonacci ConnectionBrian Smith2016-02-14 12:00:22
SolutionFibonacci ConnectionBrian Smith2016-02-10 12:11:57
SolutionGeneralisationFrankM2008-02-03 11:20:29
Worst case answerTyryt2007-08-14 17:38:02
Some ThoughtsAn algorithm for potentially determining exact solutiongregg2006-10-24 23:04:56
Some ThoughtsA little bit closerJoel2006-10-20 17:48:05
Some Thoughtsre(2): New high - MarvelousJoel2006-10-20 13:24:22
a scenario that always worksCyriis2006-10-20 13:13:34
Some Thoughtsre: New high - MarvelousLeming2006-10-19 15:50:48
New highJoel2006-10-19 12:14:51
Not opimum: 48Jer2006-10-19 11:44:36
re: A better solutionLeming2006-10-18 15:43:46
Some ThoughtsA better solutionJoel2006-10-17 22:32:55
Some Thoughtsinformation theory vs. practicalitiesCharlie2006-10-17 15:25:05
Some Thoughtsthoughtssiddhesh2006-10-17 14:47:51
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