# Defective stack of coins puzzle

841.8K 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-

### School time riddle

A boy leaves home in the morning to go to school. At the moment that he leaves the house, he ...Read More »### Missing Pound Riddle

To buy new Laptop Jacob took money from his two elder brothers John and Thomas. They each give 10£ to ...Read More »### How many 6 digits can be formed puzzle

How many six digit numbers can be formed using the digits 1 to 6, without repetition such that the number ...Read More »### Lilypad’s size puzzle

A lilypad doubles in size each day. In 28 days, the lilypad will cover the entire pond. In how many ...Read More »### What Comes Next?

5 25 29 85 89 ?Read More »### Sophie’s favorite plant puzzle

Sophie who is a housemaid, She knows her boundaries well. She is good at equations. Her favorite vegetable is cauliflower. ...Read More »### Coin on table riddle

You are sitting with one opponent at an empty, round table. Taking turns, you should place one euro on the ...Read More »### Boris and Natasha

Boris and Natasha live in different cities in a country with a corrupt postal service. Every box sent by mail ...Read More »### Blue in day

I am blue at day and black at night; I do contain some creatures born and died. What am I?Read More »### What is the chance that the last passenger will get his seat?

There are 100 passengers boarding a 100 passenger airplane. When passenger 1 gets onto the plane, he is dissoriented, so ...Read More »### Throwing in the sea puzzle

If you drop a yellow hat in the Red Sea, What does it become?Read More »### Interview with fun riddle

During an interview in a renowned company, while answering the question, the candidate became quite nervous. The interviewer was generous ...Read More »### To help celebrate the New Year, we’ve decided to give you a New Year’s toast. There’s just one catch….you’ll have to solve the puzzle first!

Answer the clues below to find each word. Then place the letters on the lines below. Each letter must be ...Read More »### He ___ up from his seat to give her a ___

What is it?Read More »### Drunken walking puzzle

A drinker is walking on a road. He takes 5 step forward and then come back 3 step. His one ...Read More »### Sweet Potato riddle

A mother has four children and two sweet potatoes. How can she feed each an equal amount of sweet potatoes? ...Read More »### How many 9s riddle

Write numbers from 1 to 100…. how many 9s do you see?Read More »### Fingers Multiplication tricky puzzle

Assume there are approximately 5,000,000,000 (5 billion) people on Earth living presently. What would you estimate to be the result, ...Read More »### For meeting her dreams riddle

A girl goes to her mother’s funeral and meets the man of her dreams but she doesn’t get his name ...Read More »### Fastens Two in One

What fastens two people yet touches only one?Read More »

Accenture Interview PuzzlesAdobe Interview PuzzlesAmazon Interview PuzzlesAnalytical MathematicsAptitude PuzzleBrain TeasersCritical Thinking Puzzledata analyticsdifficult riddleEasy Math puzzlesEasy puzzlesEnglish Riddlefamous puzzleFunny RiddlesGeneral KnowledgeHard Puzzlehard puzzlesIAS Interview Puzzleinterview questionInvestigation Puzzlesknowledge puzzlelateral thinking puzzleLogic Puzzlesmathmathematical puzzleMicrosoft Interview PuzzlesMystery PuzzlesNDA Aptitude QuestionOptical illusion puzzleout of boxPicture 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