I just started physics this year, and we were assigned our first problem today. Before I continue I'd just like to stress that I am not looking for an answer. Just a hint, or something to help me out. Telling me that I'm on the right path would be helpful as well(adsbygoogle = window.adsbygoogle || []).push({});

Here's the problem:

-There are 12 coins, out of the 12 one is a counterfit.

-11 of the coins weigh the same, the counterfit weighs either more or less than a 'normal' coin.

-The only tool that may be used to solve this problem is a balencing scale, and it may be used only3 times

So far I've come up with this:

Start off with 3 groups of 4 coins each.

Use Scale 1Put two groups of 4 on each side of the scale, if they balence then you know that those 8 are all 'real' coins.

From here on I don't know what to do. I believe that you need to use groups of 4, but I'm not positive. What I do know is that you will need 2 procedures, 1 for if the first 2 groups balence, and one for if they don't.

Is my current thinking correct?

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# Homework Help: Brain Teaser Type Problem

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