A Brillian Deception

A witch owns a field containing many gold mines. She hires one man at a time to mine this gold for her. She promises 10% of what a man mines in a day, and he gives her the rest. Because she is blind, she has three magic bags who can talk. They report how much gold they held each day, and this is how she finds out if men are cheating her. 

Upon getting the job, each man agrees that if he isn't honest, then he will be turned into stone. So around the witch's mines, many statues lay! 

Now comes an honest man named Garry. He accepts the job gladly. 

The witch, who didn't trust him said, "If I wrongly accuse you of cheating me, then I'll be turned into stone."  

That night, Garry, having honestly done his first day's job, overheard the bags talking to the witch. He then formulated a plan... 

The next night, he submitted his gold, and kept 1.6 pounds of gold. Later, the witch talked with her bags.

The first bag said it held 16 pounds that day. The second one said it held 5 pounds. The third one said it held 2 pounds. 

Beaming, the witch confronted Garry. "You scoundrel, you think you could fool me. Now you shall turn into stone!" the witch cried. One second later, the witch was hard as a rock, and very grey-looking.

How did Garry brilliantly deceive the witch? 

Here is the Garry's Master Plan!
 

Mathematics Behind The Brilliant Deception!

What was the deception?

As per the honest man, he must have mined 16 Pounds of gold since he kept 1.6 Pounds (10% of 16) gold for himself.

And as per magical bags, since Bag no.1 said it had 16 Pounds, Bag no.2 said 5 Pounds and Bag no.3 said 2 Pounds the total gold mined 16 + 5 + 2 = 23 Pounds.

We know, honest man Garry would never do any fraud and neither of magical bag would lie. 

So, it's clear that some of pounds are counted multiple times by magical bags. There are 23 - 16 = 7 Pounds gold extra found by those bags.

Now, Bag No.3 must have 2 Pounds in real.

And to make count of Bag No.2 as 5, Garry must had put 3 Pound + Bag No.3 itself in Bag No.2. Hence, the Bag No.2 informed witch that it had total 5 Pound of gold.

Finally, to force Bag No.1 to tell it's count as 16, Garry must had put 
11 Pounds + Bag No.2 (5 Pounds = 3 + Bag No.1) = 11 + 5 = 16 Pounds.

In short, Garry put 2 pounds of gold in Bag No.3 and put that Bag No.3 in Bag No.2 where he had already added 3 Pounds of gold. After that, he put this Bag No.2 in Bag No.3 where he had already added 11 Pounds of gold (somewhat like below picture).

 

This way, 2 Pounds of gold in Bag No.3 are counted 2 extra times and 3 Pounds gold of Bag No.2 are counted 1 more extra time. That is 2 + 2 + 3 = 7 Pounds of extra gold found by bags.

The Challenge Ahead of New Manager

In a wood-cutting factory, five large sawing machines stand in a windowless room. Each machine has an on/off switch attached, there being no doubt as to which switch controls which machine.

Outside the door to the room are five back-up on/off switches, one for each machine inside. The power for each machine must first pass through the back-up switch, and then the machine switch before reaching the saw.

The problem is, the new manager cannot decide how these back-up switches match with the machines inside the room. One day, the manager's brother visits. The manager takes him inside the sawing room where all five machines are at work and explains the problem. The brother announces that he intends to leave the room and that when he returns he will be able to match correctly the five switches outside the room to the five machines inside. The brother works alone, cannot see the machines from outside the room and solves the problem purely by operating switches. 

How is it possible?

Read how brother managed to do it! 

Genius Moves by Brother of Manager!

What was the challenge?

Suppose you are the brother of that manager & have accepted the challenge. 

For sake of convenience, we will name switches inside the room operating machines as an 'operating switches' & those which are outside the room as a 'back up switches'.

Though windowless, we assume that operating sound of machine(s) can be heard from outside room but can't see which machine(s) is (are) in operating condition. 

Here is what you should do!

1. Let's label the machines which we are going to keep ON as ACTIVE & others as INACTIVE. 

2. Turn off operating switches of 2 machines so that there are three machine ACTIVE and two are INACTIVE inside the room.

3. Go outside and now your task is to find the 3 back up switches controlling 3 active machines inside the room.

4. You have to switch off three switches in all possible combinations. There are 10 such possible combinations (5C3) of 3 controlling switches out of 5.

5. If 0 represents OFF position and 1 represents ON position then you should try all possible below combination. 

11000
10100
10010
10001
01100
01010
01001
00110
00101
00011

6. There will be exactly one combination in which all three ACTIVE machines  will be OFF & there will be no sound coming out of the room. The three switches having value of 0 are controlling ACTIVE machines while other 2 must be controlling INACTIVE machines.

7. Still we don't know the exact switch operating the each machine. Label 3 switches controlling ACTIVE machines as A, B and C & those controlling INACTIVE machines as D & E. 

Allow some time to cool down all those ACTIVE machines.

8. Now, turn on 2 switches A & B and keep switch E ON. Machines connected to A and B will start working.

9. After a while, turn off the switch B and go inside the room. 

10. The machine which is still operating must be controlled by back up switch A.

11. Touch other 2 which were labelled as ACTIVE & check which has got warmer.

12. The machine which is warmer must be controlled by back up switch B.

13. And since we didn't turn on the switch C (after giving time all to cool down), the machine having normal temperature must be controlled by the switch C.

14. Remember, we had turned off operating switches of INACTIVE machines initially. And before entering into room again we have turned on switch E. 

15. Now, turn on operating switch of one of the INACTIVE labelled machine. 

If the machine starts working it must be connected to the switch E & other to the switch D. And if the machine doesn't start working it must be connected to D & other to E. 

This way, you will find every back up switch located outside the room controlling operating switch of each machine inside the room.

 

Poisonous Drink

Marissa and Juliana went out for drinks together. They ordered the same drink. Juliana was really thirsty and finished five in the time it took Marissa to finish one. The drinks were poisoned, but only Marissa died. How?

TIP : Poison wasn't in Marrisa's glass neither added externally by any one.

This is how Juliana survived! 

Harmless Poisonous Drink

What was the incident?

That's because the poison was in the ice. Since Marissa took time to drink her first, the ice melted & poison got mixed up in the drink very well. Whereas, Juliana was thirsty & finished drinks in hurry; it didn't get enough time to melt the ice & hence poison didn't get mixed up with the drink. That's how Juliana survived!

What color was the bear?

I left my campsite and hiked south for 3 miles. Then I turned east and hiked for 3 miles. I then turned north and hiked for 3 miles, at which time I came upon a bear inside my tent eating my food! What color was the bear?

Yes, it can be answered!

'THIS' Was The Color of Bear!

Wait,first read the question! 

There is only one place on earth where when you hike 3 miles south then 3 miles east followed by 3 miles north & eventually end at the same starting point. And that place is north pole. 

Only Polar bears can survive on north pole; and they are white in color.

Hence, the bear found must be of white color. 

Which way is the bus going? Left or Right?

Can you guess in which direction this bus is going?

Are you in the right direction?

Bus is Moving In 'This' Direction!

Why dirction was asked to find? 


Well, it totally depends on the location of the bus. How? Read further.

If you look at it carefully, then you can notice that the doors of the bus are missing.
That clearly indicates, those must be on the other side of bus.

Hence if bus is on the roads of India then it must have doors at it's left side & hence the bus must be moving in the right direction.

While in some countries, bus might have doors at the right; in the case the bus must be moving in left direction. 

Who Stole The Money?

A man placed a $100 dollar bill on his desk and left for work. When he returned back the money was gone. He has three suspects: the cook, the maid and the electrician.

The cook said he put the bill under a book on his desk to keep it safe. The man checked and it is no longer there.

The maid said she moved the bill to the inside of the book between page 1 and 2 while she was cleaning. Again, the man checked the book and there was nothing between page 1 and 2.

The electrician said he saw the bill sticking out of the book and he moved it between page 2 and 3 to keep it safe.

Who stole the money?

Know who is the thief? 

The Electrician Stole The Money

Who were other suspects?

The electrician must be lying. Since the man checked between page 1 and 2 the next pair of page must be 3 and 4 not 2 and 3. The page numbers 2 and 3 must be the part of single page. 

So how can electrician move it between page 2 and 3? 

Wrong Looking Correct Mathematical Equation!

The following question it puts forth you:

25 - 55 + (85 + 65) = ?

Then, you are told that even though you might think its wrong, the correct answer is actually 5!

Whats your reaction to it? How can this be true? 

 That's how it's perfectly correct!

That's How Equation is Correct!

Why it was looking wrong? 

If you read the data carefully then you will notice '!' attached to number 5 which is being claimed answer. Actually claimed answer is 5! not 5 Read it again...

"Then, you are told that even though you might think its wrong, the correct answer is actually 5!."

Now use of '!' is not limited to the sentences only. In mathematics it's a 'factorial'.

So 5! = 5 x 4 x 3 x 2 x 1 = 120 and 25 - 55 + (85 + 65) = 120 and hence,

25 - 55 + (85 + 65) = 5! 

Now doesn't it look the correct equation? 

A Car on a Fragile Bridge

A car is crossing a 20km long bridge. The bridge can support at most 1500kg of weight over it. If somehow, the weight on the bridge becomes more than that, it will break.
Now, the weight of the car is exactly 1500kg. At the midway, a bird comes and sits on the roof of the car. This bird weighs exactly 200 gram. 

 
Can you tell if the bridge breaks at this point or not? 

Read what will happen next? 

Source 

 

Bridge Under Load

What was the situation?

At first look, the first impression would be that the bridge will break certainly. But if you wait for a while before concluding anything you will get the right answer.

The bridge will not break in the case! It's 20 km long bridge & now it's in the middle of bridge after traveling 10 km. By now, it must have used half of the fuel that was in the tank initially at the start. This amount of fuel must be weighing more than 200 gm. Hence even a bird sits on the car there are hardly any chances the total weight on the bridge goes beyond 1500 kg! Hence, no chance of breaking of it.

 

Mixture of Coffee and Tea

Suppose we lay down two cups in front of you. One of the cups is filled with tea and the other one with coffee. Now we ask you to take a spoonful of tea and mix it with the coffee. 

At this moment, the coffee cup has a mixture of tea and coffee. You have to take that mixture (spoonful) and add it back to the tea. 

Can you now tell if the cup of coffee has more tea or the cup of tea has more coffee ?

Skip to the answer! 

Source 

Component Levels in Mixture

How mixture made?

After adding 1 spoon of tea into coffee, the levels of liquids in both cups must be unequal. Whatever now tea cup is missing is now in cup of coffee & mixed with coffee. The content of tea in the cup of coffee is certainly more.

Now after taking spoonful of the mixture back to tea cup the levels of the liquid in both cups would be same. Hence, whatever the cup of tea is missing is replaced by coffee. That missing tea content is now in the cup of coffee where it has replaced some of coffee content! 

Suppose there are 1000 molecules in each cup i.e. of tea & coffee. Let's assume 100 molecules of tea are mixed to coffee using spoon. Now, coffee cup will have 1100 molecules and tea will have 900 molecules. Obviously, right now the cup of coffee contains more tea (100 molecules) that coffee in cup of tea (0 molecules)!

Now while taking 100 molecules back from mixture having 1100 molecules, suppose 70 molecules of coffee & 30 of tea are taken. That means, exactly 100 - 30 = 70 molecules of tea left in mixture. That 70 + 30 molecules mixture is poured into cup of tea. That is exact 70 molecules of coffee mixed in tea.

What does it mean? 70 molecules of coffee have displaced 70 molecules of tea into cup of coffee maintaining level of both the liquids. 

We can say other way as well. 30 molecules of tea displaced 30 molecules of coffee into cup of tea while maintaining levels of both the liquids same. 

So the answer is both have same level of contents mixed.

 

An Insepection by The Superintendent

One day, a class teacher was told that the school superintendent will be visiting her class on the next day. The superintendent can ask questions from anywhere and it can be easy as well as difficult. The teacher will have the liberty to choose any pupil for answering the question.

Now she is determined that the impression that is cast upon the superintendent after the inspection should be great. How will she instruct the students so that she maximizes the chances of receiving a correct answer for each question? Also, she must create the best impression. How will she do it? 

This is what she should do! 

To Impress Superintendent

What was the resolution of teacher? 

Now what should teacher do here is to devise the 'sign' language to communicate with students. Also she needs to make sure that the superintendent won't have any doubt while questioning students.

She should ask all the students to raise hands for every question that is being asked by superintendent. However, those who know correct answers should raise right hand & rest of all should raise left hand. This way she would be able to know the students who knows the correct answer & choose any of them to answer the question.

All raised hands to each question would definitely leave great impression on the superintendent.

Note : We are assuming superintendent not smart enough to notice that students raising different hands for different questions.