# 100 piles of coins and one Counterfiet?

There are 100 piles of coins in a warehouse, each coin is supposed to have a mass of one gram. However, one of the piles is counterfeit. Itās coins have a mass of 3/4 of a gram. How can you find the counterfeit pile by using an electric scale one and only once?

Related posts:

- You have fifteen piles of coins, each pile containing twenty coins. The coins appear to be identical in…? every respect; however, they are not. Fourteen of the piles contain coins that weigh 2 grams each, but one pile is counterfeit, and those coins weight 2.1 grams each. You...
- you are given 3 piles of ten peso coins. 1 pile is made up of counterfeit coins,heavier than the genuine ones.? you are given 3 piles of ten peso coins. 1 pile is made up of counterfeit coins,heavier than the genuine ones. explain how you can pick out the pile of...
- counterfiet coin puzzle? there are ten stacks of ten silver dollars. you are given the weight of a real silver dollar, and are told each counterfeit coin weighs one gram more than a...
- There are nine identical- looking coins. One of the coins is counterfiet and weighs less than the other coins. The only scale available is a balance scale, on which you can weigh any number of coins against each other. Using the scale only twice, figure out a way to...
- Riddle! There are ten stacks of ten gold coins on a table…? You are told the weight of the coins and guaranteed that nine of the stacks contain real gold coins. The tenth stack has all counterfeit coins that weigh exactly one...

I was thinking along the same lines as the first answerer. My way is that you put all the piles on the scale, and remove them one by one. Whichever one reduces the reading by 3/4 gram is the counterfeit.

label the piles from 1 to 100. take coin(s) as indicated on their labels (a coin from pile 1, 2 coins from pile 2, and so on) and put all of them together on the scale. find the difference of weight the pile is with the weight it usually does if theres no counterfeit. time by 4(or actually divide by 1/4). thereās ur answer(the pile labelled with that number)

u should have 100(1+100)/2=5050 coins in the pile u weight.

the "un"counterfeit weight=5050 grams.