Use a scale that is accurate to within 0.01 grams to measure the weight of the coin. Compare your results to that of the genuine coin. If they are significantly off, you may have a counterfeit coin. Use an extremely strong magnet to see if the coin is attracted to it.
How do you find the heavier coin?
two weighings are needed. separate into three groups (3,3,2) put three on each side of scale, if sides balance then place two remaining coins on either side of scale to see which is heavier.
Which coin is the heaviest?
The Perth Mint created the “1 Tonne Australian Kangaroo” in 2011 to bring worldwide attention to its popular annual Australian Kangaroo Gold Bullion Coin Series. A year later, Guinness World Records affirmed its status as the world’s largest coin.
Can you spend a 20 dollar coin copy?
No, replicas are not legal tender. Under the U.S. Constitution, only the federal government can mint legal tender coins. Replicas of U.S. coins cannot be exchanged as legal tender or used as money.
Are copy coins real gold?
A copy coin is a coin that uses a design from a popular coin. Although these coins may be made of precious metals, they are generally made with only a fraction of what a proper gold coin would be made out of. For instance, the coin may only consist of 60 percent gold, rather than the proper percentage of 91.6.
How can you tell the difference between a coin and a counterfeit?
We will give the Real coins a weight value of 1 and the fake a weight value of 2. Take any six coins of the eight coins, put 3 on the left side and three on the right side. If both sides equal 3, remove all six and weigh the remaining two. One of the two will be the fake coin and the second weighing will reveal it.
Can you put a fake coin on a balance scale?
Solution. One weighing. Place one coin on one side of the balance scale, one on the other, and put one coin aside. If the scale balances, the coin that we put aside is fake. If one of the sides of the scale is heavier, the fake coin is on that side. Example 2. One of the nine identically looking coins is fake.
How many coins are in a fake coin stack?
If you weigh 41 coins on each scale, and it tips left or right, then you have narrowed the fake coin down to one of the 82 coins you weighed. Since 82 > 3 4, you cannot determine which is the fake coin in only four more weighings. Thus, you can weigh at most 40 coins on each scale in the first weighing.
How to narrow it down to one fake coin?
From there, continually divide 1 / 3 of that group against another 1 / 3 to narrow it down to the fake coin. If the first weighing did not balance, then you have narrowed it down to either one of he coins on the heavy pan is heavy or one of the others is light. 80 possibilities. From here, you need to narrow the possibilities down by factors of 3.
