Nine Gold Coins

[danyj]

Bob has nine gold coins, however one of the nine gold coins is fake. The fake gold coin is lighter than the real gold coin. He also has a scale (the old kind). Is it possible for Bob to figure out which gold coin is fake with just 2 measurements? If so, how? Good Luck!!

[100%]

Counterfeiting is Illegal

:rtfaq:

[sexfem]

1. Two sets of three
If they balance*, then

2. one of the other three on each side.
if the dont balance then you know the answer.
If they do balance then the one left is the lighter.

* If they dont balance then one of the lighter one on each side.
if the dont balance then you know the answer.
If they do balance then the one left is the lighter.


Incidentally my name is bob.

******

Now try the same thing with 12 coins, only this time you have three shots. but you dont know whether the coins is lighter or heavier. Good luck.

[DanB]

I got so confused between if they do and if they don't that I can't tell if you are right

[sexfem]

Originally posted by danb@24 April 2004 - 19:47
I got so confused between if they do and if they don't that I can't tell if you are right

There is a formula Dan. But I have forgot it.

[danyj]

1. Two sets of three
If they balance*, then

2. one of the other three on each side.
if the dont balance then you know the answer.
If they do balance then the one left is the lighter.

* If they dont balance then one of the lighter one on each side.
if the dont balance then you know the answer.
If they do balance then the one left is the lighter.


Incidentally my name is bob.   

******

Now try the same thing with 12 coins, only this time you have three shots. but you dont know whether the coins is lighter or heavier. Good luck.

WRONG!!!!!
























i mean yes you are correct

[Marius24]

spend them all. no more fake coin