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## #1 2013-10-11 22:13:05

gAr
Star Member

Online

### Find the mass of the coins

There are 13 piles, each having 4 coins. One of the piles contains 4 counterfeit coins.
The genuine coin's 'x' grams (a positive integer), and the counterfeit coin's x+Δ grams (Δ is a non-­zero
real number strictly between ­-5 and +5). Having a precise digital scale, determine x, Δ, and the pile containing the counterfeit coins using the scale only twice.

"Believe nothing, no matter where you read it, or who said it, no matter if I have said it, unless it agrees with your own reason and your own common sense"  - Buddha?

"Data! Data! Data!" he cried impatiently. "I can't make bricks without clay."

## #2 2013-10-12 09:31:22

anonimnystefy
Real Member

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### Re: Find the mass of the coins

I think I have it! I'll edit this post to include the answer:

Last edited by anonimnystefy (2013-10-12 09:40:57)

The limit operator is just an excuse for doing something you know you can't.
“It's the subject that nobody knows anything about that we can all talk about!” ― Richard Feynman
“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment

## #3 2013-10-12 14:53:58

gAr
Star Member

Online

### Re: Find the mass of the coins

"Believe nothing, no matter where you read it, or who said it, no matter if I have said it, unless it agrees with your own reason and your own common sense"  - Buddha?

"Data! Data! Data!" he cried impatiently. "I can't make bricks without clay."

## #4 2013-10-12 20:40:26

anonimnystefy
Real Member

Offline

### Re: Find the mass of the coins

Thanks! I like this puzzle a lot!

The limit operator is just an excuse for doing something you know you can't.
“It's the subject that nobody knows anything about that we can all talk about!” ― Richard Feynman
“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment

## #5 2013-10-12 21:45:36

gAr
Star Member

Online

### Re: Find the mass of the coins

You're welcome!

"Believe nothing, no matter where you read it, or who said it, no matter if I have said it, unless it agrees with your own reason and your own common sense"  - Buddha?

"Data! Data! Data!" he cried impatiently. "I can't make bricks without clay."