# If you have 8 coins and a balance scale. The coins look alike, but 1 is counnterfeit and lighter than the othe

If you have 8 coins and a balance scale. The coins look alike, but 1 is counnterfeit and lighter than the other 7. Which is the counterfeit coin using 2 weighings on the balance scale?

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1. PLACE THREE COINS ON BOTH SIDES OF THE BALANCE.

IF IT BALANCES:

2. Remove them all and place the other two; one on each side. It will not balance so the lighter side has the counterfeit.

IF IT DOES NOT BALANCE:

2. Remove all the coins from the heavy side, place one each from the three left on the lite side on each side of the balance and keep the other one in your hand. If it balances the one in your hand is the counterfeit. If it does not; obviously, the lighter one is counterfeit.

Try putting one coin on the scale with another one. Keep switching the right side of the scale until you find the one that is lighter.

-L

Not possiable to determine with that information if you can only weigh twice that would mean you could weigh 4 and 3 you would need atleast 5 weighs to figure that out.

First you put four coins on one side and four on the other. You discard the four heavier coins, those are genuine.

Then you take the four lighter coins and weigh two against two.

Now you have it down to two coins. Take the two lighter coins, and it’s one of those.

Now if you could balance both those coins you’d have it. But you said it’s only two weighings. So I’m stuck. Maybe you could spend both those coins in different places and see which time you get arrested.

Put 3 coins on either side of the scale.

If it’s even then the light one can be determined by comparing the other two remaining coins. Otherwise…

Take two of the three coins that were on the light side and place one on each side of the scale. If the they are the same, then the third coin is the light one, otherwise you’ll be able to tell from which is lighter.