# Defective stack of coins puzzle

There are 10 stacks of 10 coins each.

Each coin weights 10 gms. However, one stack of coins is **defective** and each coin in that stack weights only 9 gms.

What is the minimum number of weights you need to take to find which stack is defective? How?

**SOLUTION-** 1 Measurement Only

**EXPLANATION-**

We will take,

1 coin from the first stack,

2 coins from the second,

3 from the third

and

so on.

In total we will have 55 coins.

If all of them were non-defective, they would weigh 550 gms.

If stack 1 is defective, the measure would read 549 gms.

If stack 2 is defective, you will read 548 gms.

and so on.

So by taking **one measurement** you can identify, which is the defective stack.

### Your Answer

## More puzzles to try-

### What is the logic behind these ?

3 + 3 = 3 5 + 4 = 4 1 + 0 = 3 2 + 3 = 4 ...Read More »### Five greedy pirates and gold coin distribution Puzzle

Five puzzleFry ship’s pirates have obtained 100 gold coins and have to divide up the loot. The pirates are all ...Read More »### Dr. Willam and surgical gloves puzzle

Dr.Willam wants to operate for three different persons who were wounded. But he had only two surgical gloves. There is ...Read More »### Which clock works best?

Which clock works best? The one that loses a minute a day or the one that doesn’t work at all?Read More »### To which one will the needle touch 1 OR 2

In the gear arrangement, To which one will the needle touch, 1 OR 2Read More »### How did he know?

A man leaves his house in the morning to go to office and kisses his wife. In the evening on ...Read More »### Which letter replaces the question mark

Which letter replaces the question markRead More »### Crossing the Bridge Puzzle (Bridge and torch problem)

A bridge will collapse in 17 minutes. 4 people want to cross it before it will collapse. It is a ...Read More »### Probability of having boy

In a country where everyone wants a boy, each family continues having babies till they have a boy. After some ...Read More »### Magical flowers!!

A devotee goes to three temples, temple1, temple2 and temple3 one after the other. In front of each temple, there ...Read More »### How many times a day do all three hands of analog watch overlaps?

There is a perfectly accurate analog watch with hour, minute, and second hands. How many times a day do all three ...Read More »### Tuesday, Thursday what are other two days staring with T?

Four days are there which start with the letter ‘T‘. I can remember only two of them as “Tuesday , Thursday”. ...Read More »### How could only 3 apples left

Two fathers took their sons to a fruit stall. Each man and son bought an apple, But when they returned ...Read More »### How Many Eggs ?

A farmer is taking her eggs to the market in a cart, but she hits a pothole, which knocks over ...Read More »### Minimum number of persons needed to cross a Desert

In the middle of the confounded desert, there is the lost city of “Ash”. To reach it, you will have ...Read More »### Lateral thinking sequence Puzzle

Solve this logic sequence puzzle by the correct digit- 8080 = 6 1357 = 0 2022 = 1 1999 = ...Read More »### Pizza Cost Math Brain Teaser

Jasmine, Thibault, and Noah were having a night out and decided to order a pizza for $10. It turned out ...Read More »### Which room is safest puzzle

A murderer is condemned to death. He has to choose between three rooms. The first is full of raging fires, ...Read More »### Overthrow your math teacher!

Some numbers are very mysterious. They are all integers. They have more than one digit. If you multiply them with ...Read More »### Richie’s Number System

Richie established a very strange number system. According to her claim for different combination of 0 and 2 you will ...Read More »

## Tags

Accenture Interview PuzzlesAdobe Interview PuzzlesAmazon Interview PuzzlesAnalytical MathematicsAptitude PuzzleBrain TeasersCognizant Interview PuzzlesCritical Thinking Puzzledata analyticsdifficult riddleEasy Math puzzlesEasy puzzlesEnglish Riddlefamous puzzleFunny RiddlesGoogle Interview PuzzlesHard Puzzlehard puzzlesIAS Interview Puzzleinterview questionInvestigation Puzzlesknowledge puzzlelateral thinking puzzleLogic Puzzlesmathmathematical puzzleMicrosoft Interview PuzzlesMystery PuzzlesNDA Aptitude QuestionOptical illusion puzzleout of boxPicture Brain TeasersPicture Puzzleprobability puzzlesPuzzlePuzzle For KidspuzzlesPuzzles for interviewRiddleRiddles for KidsSherlock Holmes Mystery PuzzlesShort PuzzlesStupid logic puzzlesTricky PuzzleTricky PuzzlesTricky RiddleVisual Logic puzzleWhat is it puzlleWhatsapp PuzzlesWho am i puzzle