perplexus.info :: Weights and Scales : One of Sixteen

One of Sixteen (Posted on 2015-12-29)

I have two sets of 8 coins. In one set the coins weigh 30g each, in the other set the coins weigh 31g each.
Unfortunately they got mixed together in one big pile of 16 coins. I want to identify one coin. It can be from either set.

(Easy) Using a balance scale, identify a coin in four weighings.

(Hard) Identify a coin in just three weighings.

See The Solution Submitted by Brian Smith

Rating: 4.0000 (3 votes)

Comments: ( Back to comment list | You must be logged in to post comments.)

re: What's the problem? (and a spoiler)

| Comment 7 of 12 |

(In reply to What's the problem? (and a spoiler) by Steve Herman)

The problem is to identify any one coin. It does not need to be a specific coin. Broll's solution is correct.

I don't think it is possible to choose and identify a specific coin in just three weighings.

Posted by Brian Smith on 2015-12-31 13:06:07

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