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Time for a workout!

In front of you, there are 9 coins. They all look absolutely identical, but one of the coins is fake. However, anda know that the fake coin is lighter than the rest, and in front of anda is a balance scale. What is the least number of weightings anda can use to find the counterfeit coin?
Time for a workout!
 wantadog posted lebih dari setahun yang lalu
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Kragfan1910 said:
2.
Let me explain my reasoning.
So, I'm making the assumption anda don't know the weight of the coin, that this isn't a bullion coin with a labeled "1 troy ounce" atau anything along those lines.
So let's say anda weigh a coin, and it comes in one half of a troy ounce, is that the real coin atau the fake one? anda don't know, until anda weigh a detik one, and it comes in at a full troy ounce, anda now now that your first coin is significantly lighter, and it is therefore the counterfeit coin.
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posted lebih dari setahun yang lalu 
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So even if anda weighed the counterfeit coin first, anda still need a sort of bearing, atau a control group before anda can know which of the coins is lighter than the rest.
Kragfan1910 posted lebih dari setahun yang lalu
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Alternately, anda can solve it with math, materials science, and a beaker of water. If anda get lucky and weigh a coin, and it comes out at a half a troy ounce, use the beaker to find the volume, and calculate the density, then anda can compare its density to the density of the material the coin should be made out of, be it copper, nickel, atau silver, and see if it matches, atau if it falls short and matches the density of aluminum atau titanium, if anda use that method, the minimum amount of weighings would be 1.
Kragfan1910 posted lebih dari setahun yang lalu
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At least, that's what my friend Kalispel says. :P
Kragfan1910 posted lebih dari setahun yang lalu
8theGreat said:
2.








I mean... not really too difficult...
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posted lebih dari setahun yang lalu 
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Hopefully the next'll be harder
wantadog posted lebih dari setahun yang lalu
Riku114 said:
Dont.

Dont weight them at all. If they look identical and the difference in weight is not so obvious that anda cant tell oleh holding them, dont. Pretend its real and spend it.
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posted lebih dari setahun yang lalu 
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^ Smartest post here.
Kragfan1910 posted lebih dari setahun yang lalu
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^ i agree
hplover321 posted lebih dari setahun yang lalu
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