# Defective stack of coins puzzle

1,045.5K Views

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 »### 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 »### (Advanced) Cheryl’s Birthday Puzzle

Paul, Sam and Dean are assigned the task of figuring out two numbers. They get the following information: Both numbers ...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 »### 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 »### Most Analytical GOOGLE INTERVIEW Question Revealed

Let it be simple and as direct as possible. Interviewer : Tell me how much time (in days) and money would ...Read More »### Lateral thinking sequence Puzzle

Solve this logic sequence puzzle by the correct digit- 8080 = 6 1357 = 0 2022 = 1 1999 = ...Read 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 »### 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 letter replaces the question mark

Which letter replaces the question markRead 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 »### 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 »### Srabon wanted to pass

The result of math class test came out. Fariha’s mark was an even number. Srabon got a prime!! Nabila got ...Read More »### Become Normal!!

Robi is a very serious student. On the first day of this year his seriousness for study was 1 hour. ...Read More »### Sakib Knows The Number!

Ragib: I got digits of a 2 digit number Sakib: Is it an odd? Ragib: Yes. Moreover, the sum of ...Read More »### Maths Genious Riddle

If u r genius solve it:- 40 * 14 = 11 30 * 13 = 12 20 * 12 = ...Read More »### Calling 2 as 10 Riddle

When do we call “10” while looking at number “2”?Read More »### 2 Eggs and 100 floor Google Classic question

There is a building of 100 floors -If an egg drops from the Nth floor or above it will break. ...Read More »

Accenture Interview PuzzlesAdobe Interview PuzzlesAmazon Interview PuzzlesAnalytical MathematicsAptitude PuzzleBrain TeasersCognizant Interview PuzzlesCritical Thinking Puzzledifficult riddleEasy Math puzzlesEasy puzzlesEnglish Riddlefamous puzzleFunny RiddlesGeneral KnowledgeHard Puzzlehard puzzlesIAS Interview Puzzleinterview questionknowledge puzzlelateral thinking puzzleLogic Puzzlesmathmathematical puzzleMicrosoft Interview PuzzlesMystery PuzzlesNDA Aptitude QuestionOptical illusion puzzleout of boxPermutation puzzlePicture Puzzleprobability puzzlesPuzzlePuzzle For KidspuzzlesPuzzles for interviewRiddleRiddles for KidsSherlock Holmes Mystery PuzzlesShort PuzzlesStupid logic puzzlesTIme Pass puzzlesTricky PuzzleTricky PuzzlesTricky RiddleViral PuzzlesVisual Logic puzzleWhat is it puzlleWhatsapp PuzzlesWho am i puzzle