যেভাবে খুশী

এই প্রশ্নের উত্তর দিন

যেভাবে খুশী প্রশ্ন

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, আপনি know that the fake coin is lighter than the rest, and in front of আপনি is a balance scale. What is the least number of weightings আপনি can use to find the counterfeit coin?
Time for a workout!
 wantadog posted বছরখানেক আগে
next question »

যেভাবে খুশী উত্তর

Kragfan1910 said:
2.
Let me explain my reasoning.
So, I'm making the assumption আপনি don't know the weight of the coin, that this isn't a জরির ঝালর coin with a labeled "1 troy ounce" অথবা anything along those lines.
So let's say আপনি weigh a coin, and it comes in one half of a troy ounce, is that the real coin অথবা the fake one? আপনি don't know, until আপনি weigh a সেকেন্ড one, and it comes in at a full troy ounce, আপনি now now that your first coin is significantly lighter, and it is therefore the counterfeit coin.
 select as best answer
posted বছরখানেক আগে 
*
So even if আপনি weighed the counterfeit coin first, আপনি still need a sort of bearing, অথবা a control group before আপনি can know which of the coins is lighter than the rest.
Kragfan1910 posted বছরখানেক আগে
*
Alternately, আপনি can solve it with math, materials science, and a beaker of water. If আপনি 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 আপনি can compare its density to the density of the material the coin should be made out of, be it copper, nickel, অথবা silver, and see if it matches, অথবা if it falls short and matches the density of aluminum অথবা titanium, if আপনি use that method, the minimum amount of weighings would be 1.
Kragfan1910 posted বছরখানেক আগে
*
At least, that's what my friend Kalispel says. :P
Kragfan1910 posted বছরখানেক আগে
8theGreat said:
2.








I mean... not really too difficult...
 select as best answer
posted বছরখানেক আগে 
*
Hopefully the next'll be harder
wantadog posted বছরখানেক আগে
Riku114 said:
Dont.

Dont weight them at all. If they look identical and the difference in weight is not so obvious that আপনি cant tell দ্বারা holding them, dont. Pretend its real and spend it.
select as best answer
posted বছরখানেক আগে 
*
^ Smartest post here.
Kragfan1910 posted বছরখানেক আগে
*
^ i agree
hplover321 posted বছরখানেক আগে
next question »
Cookies help us bring you Fanpop. By using Fanpop, you agree to our use of cookies. Learn More Got It!