To Identify The Counterfiet Coin!

Why it was asked to? 

1. Make a group of 3 coins each. Weigh these groups against each other.

2. If both groups weigh equal then weigh remaining 2 against each other. Heavier coin would be easily identified.

3. If one of group is heavier, then take out coins of this group.The counterfeit coin is among them.

4. Now weigh 2 of 3 coins of this group against each other.

5. If both are equal then obviously third one is counterfeit.

6. If one of them is heavier then obviously that one is counterfeit. 

 

The Safest Room - Lateral Thinking

A murderer is condemned to death. He has to choose between three rooms. The first is full of raging fires, the second is full of assassins with loaded guns, and the third is full of lions that haven't eaten in 3 years.

Which room is safest for him?

The Safest Room

Which one;find it here! 

Source 

The Safest Room - Lateral Thought

What was the puzzle?

If murderer has a little brain then he would choose the third room 

straightaway. How lions can stay alive for 3 years without eating anything? 

"He is my son"

A man and his son are in a terrible accident and are rushed to the hospital in critical care. The doctor looks at the boy and exclaims "I can't operate on this boy, he's my son!"

How could this be?



Here is that lateral thought! 

A Doctor Can Be Mother

Why it was required? 

The doctor is mother of that son!

Visual Illusions Psychology

Which monster looking bigger? The one which is chasing the other? Right?

Bigger Vs Smaller

Now look at this. What's your take now?

Equal Heights

Both are of same size. A 3D tunnel built around deceives your visual system & totally changes how it perceive things.

Now take a look at this. Are these straight lines or not? Definitely not! Right?

Straight or Curved

But you are totally wrong! Have a look at this.

Only Straight Lines

Again white & black checks surrounded in certain disorder changes how you perceive things.  

Checker Shadow illusion

Which square is darker here; A or B?

A is darker or B

The A appears darker than B here. But that's not the reality. Both shares equal levels of brightness & gray levels. A printer would you same ink to print those squares. 

Equally Darker

What's challenge to visual system here?

The task given to your visual system here is to determine the color of the object & here it is gray level. But shadow of cast plays here big role. The square under shadow reflecting less light than the one is not in shadow. Visual system need to do several tricks to compensate that shadow effect & determine the exact color of the square under shadow.

What tricks visual system uses?

1. Local contrast : Irrespective of shadow, a lighter check surrounded by more lighter checks is perceived as a check with more average lightness & vice versa. In the figure, the light check in shadow is surrounded by darker checks. Thus, even though the check is physically dark, it is light when compared to its neighbors. The dark checks outside the shadow, conversely, are surrounded by lighter checks, so they look dark by comparison.

2. Shadows often have soft edges while paints (here checks) have sharp edges. The visual system tends to ignore gradual changes in light level, so that it can determine the color of the surfaces without being misled by shadows. In this figure, the shadow looks like a shadow, both because it is fuzzy and because the shadow casting object is visible.

3. The "paintness" of the checks is aided by the form of the "X-junctions" formed by 4 abutting checks. This type of junction is usually a signal that all the edges should be interpreted as changes in surface color rather than in terms of shadows or lighting.
 
Conclusion :

The effect illustrates success rather than failure of our visual system. The illusion asking our visual system to act as a light meter; but it's definitely not built for it. What's the success of our visual system here is it breaks the information into meaningful components & then perceive different aspects of objects.



Courtesy : Wikipedia
 

Water Measurement With 2 Buckets - Puzzle

You have two buckets. One holds exactly five gallons and the other three gallons. How can you measure exactly four gallons of water into the five gallon bucket?

Assume you have an unlimited supply of water and that there are no measurement markings of any kind on the buckets.

How to measure 4 gallons?

Click here to know how it could be done? 

Source 

Water Measured Using 2 Buckets - Puzzle Cracked

What was the challenge? 

Method 1 :

1. Fill up the 3 gallons bucket & pour into 5 gallons bucket.

2. Again fill the gallon bucket & once again pour it into 5 gallons bucket. After completely filling 5 gallons bucket there will be 1 gallon left in 3 gallons bucket.

3. Empty 5 gallons bucket.

4. Pour that 1 gallon into 5 gallons bucket. Now fill up 3 gallons bucket. We have 4 gallons of water now 1 in 5 gallons bucket & 3 in 3 gallons bucket.


Method 2:

1. Fill up 5 gallons bucket & pour it into 3 gallons bucket. 2 gallons would remain in 5 gallons bucket.

2. Pour that 2 gallons of water into 3 gallons bucket. Now only space for 1 gallon left in 3 gallons bucket.

3. Again fill up 5 gallons bucket & pour into 3 gallons bucket containing 2 gallons of water left. So only 1 gallon can be poured & 4 gallons would be remaining in 5 gallons bucket. 

 

3 Switches And 1 Light Bulb

You are standing outside a closed door. On the other side of the door is a room that has a light bulbs in it. The room is completely sealed off from the outside. It has no windows and nothing can get in or out except through the door. On the outside of the room there are three light switches that controlling light bulb on the other side of the door.

Your assignment is to determine which light switch controls that light bulb. You are allowed to enter the room only once and once you come out, you must be able to state with 100% certainty which light switch controls which light bulb.

Which controls bulb?

What should you do? 

Source 

The Control Switch of Bulb

What's the matter? 

Turn ON first light switch, wait a few minutes, then turn it OFF and turn ON the second light switch. Now go to the room, if bulb is ON then second switch is controlling it. If it's OFF, then touch it & if it feels warm then first switch which you had switched ON for a while. And if it isn't warm then definitely third switch controlling the light bulb.

The Dog in Trouble

A completely black dog was strolling down main street during a total blackout affecting the entire town. Not a single streetlight had been on for hours. As the dog crosses the center of the road a Buick Skylark with two broken headlights speeds towards it, but manages to swerve out of the way just in time.

How could the driver see the dog to swerve in time?

How did I survive?

Not that much difficult! 

Source 

Time When Incident Took Place

What was the incident?

The incident happened during day time! Everything else scripted to deceive you!

Day Time

The Bus Driver

You are the bus driver. At your first stop, you pick up 29 people. On your second stop, 18 of those 29 people get off, and at the same time 10 new passengers arrive. At your next stop, 3 of those 10 passengers get off, and 13 new passengers come on. On your fourth stop 4 of the remaining 10 passengers get off, 6 of those new 13 passengers get off as well, then 17 new passengers get on. What is the color of the bus driver’s eyes?

 Find answer here! 

Source 

Color of Bus Driver's Eyes

What's the question? 

Answer is hidden in very first statement! What's color of your eyes then?

The Missing Dollar

Three travelers register at a hotel and are told that their rooms will cost $10 each so they pay $30. Later the clerk realizes that he made a mistake and should have only charged them $25. He gives a bellboy $5 to return to them but the bellboy is dishonest and gives them each only $1, keeping $2 for himself.

So the men actually spent $27 and the bellboy kept $2.What happened to the other dollar of the original $30?

Here it is found! 

Source 

The Story of Dollar That Wasn't Lost

How it was lost? 

All you need to think on the behalf of travelers to simplify things around.

Initially they spent $30 for the stay. Now these $30 distributed into 2 parts viz. 25 & 5 by clerk.  Out of 5, travelers received only 3 that means now they have spent $27 only. Out of 27, clerk had 25 & bellboy took 2! Trying to add bellboy's 2 in 27 is pointless but the base of this quiz!

Time to Fill Up The Tank

There are 2 taps to fill a big tank; one is bigger & other is smaller. A bigger alone can fill up the tank in 5 hours less than smaller tap can alone. Both taps together take 6 hours to fill up the tank.

How many hours required separately for smaller & bigger taps to fill up the tank?

Click here for answer!

Hours Needed By Each Tap

What was the question? 

Let x be hours required for bigger tap then smaller needs x + 5
hours.

In 1 hour bigger fills 1/x & smaller fills 1/(x+5) part of the tank. Together both take 6 hours to completely fill the tank. So,

1/x + 1/(x+5) = 1/6

6(x + 5 + x) = x^2 + 5x

x^2 - 7x - 30 = 0

(x-10) (x+3) = 0

x + 3 = 0 gives x = -3 which is not possible as x represents hours.

So x - 10 = 0 gives x = 10.

Hence for a bigger tap 10 hours & for smaller tap 10 + 5 = 15 hours required to fill up the tank!

Permutations or Combinations or Common Sense?

You have 12 black socks and 12 white socks mixed up in a drawer. You’re up very early and it’s too dark to tell them apart. What’s the smallest number of socks you need to take out (blindly) to be sure of having a matching pair?

To know what it is click here! 

Source 

It is Common Sense not Permutaions nor Combinations!

Question is here!

You need only 3 attempts.

Let's say on first draw we get BLACK socks. In next draw, if we get BLACK then we have matching pair immediately. But if in second draw, it's WHITE then we have to go for third draw. 

On a third draw, if it's BLACK then we have pair of BLACK socks ; one came from first draw & other from third one!

On the other hand, if we get WHITE on third draw then we have pair of WHITE socks ; one we got from second & other from third.

Same logic can be applied if WHITE comes in first draw.

Magical Number of Mangoes

Once a man collected few mangoes from a tree. Another man came & all mangoes are distributed among themselves but still 1 left. Third man came & mangoes redistributed but still 1 left. Fourth man came but still 1 left after redistribution. Fifth & sixth man came but still 1 left after re sharing. Finally, when 7th man came all mangoes distributed with no left.

How many mangoes they had?

Skip to answer! 

Finding The Magical Number

What was the teaser? 

We need to first find LCM of 2,3,4,5 & 6. It's 60. Had there been only 6 men then 61 would have been right answer. But on arrival of 7th man all mangoes distributed. So we need to find such number which is divisible by 7 & that number - 1 is divisible by 60.

Smallest such a number is 301. So they had 301 mangoes!

Checking Available Networks In All Phones

This I used to check available networks in the region before purchasing new SIM. I had found this in my first feature phone! 

1. Go to the SETTING.

2. Select PHONE.

3. Enter into NETWORK.

4. Change Operator selection to MANUAL.

5. Wait till phone scans all available networks.

6. Restore Operator Selection to AUTOMATIC otherwise it would keep asking to choose network if you go out of range for a moment.

Network Coverage

For smartphones,

1. Go to the SETTING.

2. Select WIRELESS & NETWORKS.

3. Enter into MOBILE NETWORK.

4. Select NETWORK OPERATORS.

5. Change Operator selection to MANUAL.

6. Wait till phone scans all available networks.

7. Restore Operator Selection to AUTOMATIC otherwise it would keep asking to choose network if you go out of range for a moment.

A Tiger, A Goat & A Bundle Of Grass

A man is walking down the village road with a tiger, a goat and a bundle of grass. Soon he arrives at the river bank where there is one tiny boat that can carry him and another animal or grass at a time. 

Here is the problem: Left alone, the tiger will eat the goat. And similarly, the goat will eat the grass bundle. How is he going to take all three across the river safely?

Cross The River

What should he do? 

Crossing a river with tiger, goat and grass

What is situation?

1. First he need to carry a goat across the river. Tiger won't eat a bundle of grass.

2. Then he should take a tiger (or a grass bundle) across the river.

 3. And get goat again back with him.

  4. Now he should leave a goat behind & take a grass bundle (or a tiger) with him across the river.

  
5. Finally he has to take the goat across the river in last round.

How Many Animals Are Going Towards River?

One rabbit saw 6 elephants while going towards river.

Every elephant saw 2 monkeys are going towards river.

Every monkey holds one parrot in their hands.

Now tell me how many animals are going towards river.

How Many I Saw

How many? Click here! 

There Are Total....Animals Going Towards The River!

What was the question? 

One thing is sure 1 rabbit is definitely going towards the river. And parrot is definitely not an animal; it's a bird.

Now there are 2 possibilities.

1. Every elephant saw 2 different monkeys then there are total 12 monkeys & 1 rabbit going towards river. So total 13 animals moving towards river.

2. Every elephant saw same 2 monkeys then there are total 2 monkeys & 1 rabbit going towards river. So total 3 animals moving towards river.

Actually I saw...

Biggest Possible Number?

Answered !!!

The Biggest Possible Number

View question!

Biggest Possible Number

However, 2 sticks taken from '0' can be placed ahead of  '5' & the whole image flipped vertically to get 81151.

Highest Possible Number?

Only move to 2 match sticks & form a biggest possible number.

  
Answered here!

The Highest Possible Number

   
Wait, here is question!

Just take out 2 sticks of first zero & place it like below to get 97108!

Or if it is allowed to go beyond the given space then we get, 911081.

Building Equilateral Triangles From 6 Sticks

First challenge is building 4 equilateral triangles from 6 sticks. If you managed to do so, can you make 6 equilateral triangles from 6 sticks?

Here it is done! 

Built 4 & 6 Equilateral Triangles Using 6 Sticks

Do you need to read question?

First one is pretty simple. All you need to draw a square with two diagonals. Remember rectangle will not make equilateral triangles using it's diagonals.

4 Equilateral Triangles

For the next one, form 2 equilateral triangle using 3 sticks each. Now superimpose the second one on first but upside down like below.

6 Equilateral Triangles

What Is () + () + () = 30?

What is () + () + () = 30?

Fill in blanks with 1,3,5,7,9,11,13,15.

You can also repeat the numbers. 

 Here is probable answer! 

Probable Numbers in () + () + () = 30

What's the question?

Addition of 3 odd numbers can't be even number. Here you have to do the same bringing 30 in result. So you need to do some trick. There are number of possible answers given to this question. Let's see what most common answers given.

1. Using factorial !

3! + 9 + 15 = 30.

2. Using decimal points.

11.3 + 15.7 + 3 = 30.

3. Changing base of numbers.

Assuming it in base 9 numbers,

9 + 9 + 9 = 30.

If we assume ! is allowed as in (1) which can be represented in other way,

(3x2x1) + 9 + 15 = 30

Now some body other replace that bracket with simple addition within it like,

(5+7) + 11 + 7 = 30

or

(15-13) + 15 + 13 = 30

This has to be valid as well & number of such possible combinations are valid!
 
Using decimal point is another form of this trick!

(11 + 3/10) + (15 + 7/10) + 3 = 30
 
In every above trick it's assumed that addition, multiplication, division, subtraction allowed within the bracket!
 
For the change of base, I think they would have written it in subscript of 30 otherwise infinite number of answers again. Like, if we assume it in base 5 then,

13 + 11 + 1 = 30.
 
I think, only answer with less questions is leaving first space blank & write,

+ 15 + 15 = 30

where first '+' is unary sign used to represent positive number while second one is operator for addition. Again, this comes with assumption that using only 2 numbers allowed as it's specifically not mentioned in question that you have to use all 3 numbers.

Probably this is the answer expected otherwise we need to call the creator of this for what he/she is expecting!

Magic To Reveal Age By Phone Number.

This message gone viral on whatsapp!

YOUR PHONE NUMBER. WILL REVEAL YOUR AGE.

 AMAZING -AMAZING-AMAZING

 Your Phone number will reveal your actual Age.
I do not know who discovered this?
         but it is...Really accurate.

It will take about 15 seconds,
read and do it at the same time so that you will not lose the fun.

1- Take a look at your last digit of your cell phone number

2- Use this figure and multiply by 2

3- Then add 5

4- And then multiply by 50

5-And then add the number 1766.

6- Add bonus 1 if you have celebrated your birthday this year.

7- The last step; with this number, subtract your birth year.

  First digit is  your number and last digits tell your age.

Magical Maths

Magic demystified here! 

Maths Magic Demystified.(Age By Number)

What was the magic?

Let's assume the last digit as 'x'. Now let's go step by step & see how this x is processed.

1- Take a look at your last 4 digit of your cell phone number

x

2- Use this figure and multiply by 2

2x

3- Then add 5

2x + 5

4- And then multiply by 50

50(2x+5) = 100x + 250

This puts the your mobile number's last digit at hundredth place.

5-And then add the number 1766.

100x + 250 + 1766 = 100x + 2016

6- Add bonus 1 if you have celebrated your birthday this year.

100x + 2017

7-The last step; with this number, subtract your birth year.

100x + 2017/2016 - birth year

  
How we calculate our age? If we have already celebrated birthday while calculating age, we take (current year - birthday year) or otherwise (previous year - birthday year). The simple equation applied here as well.

The Shopping Challenge

At a stationary shop, shopkeeper sells notebook at Rs.15, Pen at Rs.1 & Eraser at Rs.0.25. You are asked to purchase 100 objects & you are given Rs.100 note. 

So how many notebooks,pens & erasers would you buy?

Shopping Challenge

Here is what should you do! 

Taking The Shopping Challenge

What was the problem?

Let N = number of notebooks, P = number of pens & E = number of erasers.

From the given maths we get 2 equations as,

N + P + E = 100................(1)

15N +1P +E/4=100…....(2)
 
From (1),

P = 100 - N - E

From (2),

60N + 4P + E= 400

60N + 4(100-N-E) + E = 400

60N + 400-4N-4E + E = 400

56N - 3E = 0

56N = 3E

N/E = 3/56

From the ratio, we get, N=3, E=56.

Putting these in equation (1),

We get,

P=41.

So we should buy 56 erasers,41 pens & 3 notebooks to satisfy the given condition. 

Can You Find The Sheep Among The Santas?

Find The Sheep

Here it is spotted!

The Sheep Among Santas Spotted

Location of Sheep

Question is here!