#391 - IQ Riddle

Its a test that will check your IQ.
Suppose you have one 11 minute hourglass and one 13 minute hourglass.

Can you measure exactly fifteen minutes using them ?

IQ Riddle

First Step: Invert both the hourglasses.

Second step: When the 11 min hourglass is finished, invert it.

Third Step: When the 13 min hourglass is finished, flip the 11 min hourglass would have lost only 2 minutes till now. On inverting, we get to measure those two minutes.
Now 13 + 2 = 15 minutes.

In this way, fifteen minutes can be measured in just 3 steps.

#392 - Maths Brain Twister

Two natural numbers are having a sum less than 100 and are both greater than one.

Ned knows the product of the numbers and Shawn knows the sum of numbers.

The following conversation takes place between them:
Ned: 'I am not aware of those numbers.'
Shawn: 'I knew you wouldn't be. I am not aware myself.'
Ned: 'Now I know them!'
Shawn: 'Now I know them, too!'

What are the two numbers?

Maths Brain Twister

Product is 52 and sum is 17. The numbers are 4 and 13.

#393 - Famous Probability Problem

You are offered an opportunity of winning a fortune. There are 100 precious black stones and 100 unworthy white stones. There are two different sacks labelled as "Heads" and "Tails". You can distribute the stones as per you wish. Then a coin will be flipped. Then you will have to choose a stone from the corresponding sack. If you pick up a black stone, all the fortune of black stones is yours but if you pick up white, you get nothing.

How will you distribute the stones so that you can maximize your chances of winning?

Famous Probability Problem

If you put a single precious black stone in one bag and all the others in the other bag, it will give you almost three/fourth of the probability of picking up a precious black stone.

#394 - Mind Boggling Riddle

Sai caught 10 fishes without an I,
9 were deprived of tail
6 were headless
And half of 8
He weighed on a trusted scale
Can you find out if he asks you?
How many fishes were there in his basket?

Mind Boggling Riddle

Zero

He catches 10 fishes without an I or 1 according to Roman numeral. Taking off 1 from 10 makes it 0. Cutting the tail of 9 makes it zero. Removing the head of 6 makes it zero. Slicing 8 in half makes it zero as well. Thus in total, he caught zero fishes.

#395 - Crack The Code Puzzle

During a secret mission, an agent gave the following code to the higher authorities
AIM DUE OAT TIE MOD

However the information is in one word only and the rest are fake. To assist the authorities in understanding better, he also sent them a clue – If I tell you any one character of the code, you can easily find out the number of vowels in the code word.

Can you find out the code word?

Crack The Code Puzzle

The code word is TIE.

Suppose if you are told a character of MOD, then you can’t identify if the number of vowels are one or two. Suppose that the character you are told of is M, then you can associate two words with it i.e. AIM (that has two vowels) and MOD (that has 1 vowel). You can say the same regarding other characters O and D as well.

Thus all those words that comprises of M, O or D in them can be ruled out. This points us to TIE. If you check with the characters of TIE, you will agree that it stands true for each of the characters of the word. Thus this is the code word.

#396 - Critical Thinking Question

In a holy town, three temples sit in a row identical in almost every manner including a holy well in front of them. A pilgrim comes to visit the temples with some flowers in his basket.

At the first temple, he takes some water from the holy well and sprinkles it on the flowers to wash them. To his astonishment, the number of flowers in his basket doubles up. He offers a few of them at the temple and turns back to visit the second temple.

At the second temple, he again takes some water from the holy well and sprinkles it on the flowers to wash them. Again the number of flowers double up in number. He offers some of them at the temple and turns back to visit the third temple.

At third temple he repeats the process again and the number of flowers double up yet again. He offers all the flowers in the third temple.

Now, the pilgrim offered exactly the same number of flowers in all the temples. Can you find out the minimum number of flowers he must have had initially? How many flowers did he offer to god in each of the three temples?

Critical Thinking Question

Let us assume that there were x flowers present in the basket of the pilgrim and he offered y flowers at each temple. Now as per the details given in the question, the number of flowers when he came out of the third temple.

But the number of flowers when he comes out of the third temple must be (8x – 7y)

Thus (8x – 7y) = 0
8x = 7y

Now the minimum values that you can put by hit and trial are 7 and 8 for x and y respectively.

Thus, the pilgrim had 7 flowers in the beginning and he offered 8 flowers at each temple.

#397 - Math Deductive Reasoning Question

Five students - Adam, Cabe, Justin, Michael and Vince appeared for a competitive exam. There were total five questions asked from them from which were multiple choice questions (a, b or c) and three were true/false questions. Their answers are given as follows:

Name I II III IV V

Cabe c b True True False

Adam c c True True True

Justin a c False True True

Michael b a True True False

Vince a b True False True

Also, no two students got the same number of correct answers. Can you tell the correct answer? Also, what are their individual score?

Math Deductive Reasoning Question

The correct answers are b, a, True, False and False. Also, the scores are Justin (0), Adam (1), Cabe (2), Vince (3) and Michael (4).

Since no two students were able to answer the exact number of correct answers, there can be only two possibilities
1) 1 + 2 +3 + 4 + 5 = 15
2) 0 + 1 + 2 + 3 + 4 = 10

Now let us determine the maximum number of correct answers possible through the answers they gave.
For Question I = 2 (b or c)
For Question II = 2 (b or c)
For Question III = 4 (True)
For Question IV = 4 (True)
For Question V = 3 (True)

Now we know that the maximum number of correct answers possible are 15 (2+2+4+4+3) according to which, Adam would have given all correct answers as only he answered True for questions III, IV and V. But then Cabe and Justin would have given exactly 3 correct answers. And also, Michael and Vince would have given 2 correct answers. Therefore none of them got all the five correct answers. Thus this assumption is wrong.

The total number of correct answers therefore are 10 (0+1+2+3+4). Both Questions III and IV cannot be False as in that case, the number of correct answers would not be 10. So the student who got all wrong answers cannot be Cabe, Adam and Michael.

Suppose if Vince got all wrong, then Cabe, Justin and Michael each would have at least 2 correct answers. Thus, Adam would have to be the student with only one correct answer and in that case, the correct answers for questions I and II would be a and a respectively. But that is not possible as then the total number of correct answers would be 1 (a) + 1 (a) + 1 (False) + 4 (True) + 2 (Flase) = 9.

Thus it is Justin who has given all wrong answers. The correct answers are b, a, True, False and False. Also, the scores are Justin (0), Adam (1), Cabe (2), Vince (3) and Michael (4).

#398 - Infosys IQ Interview Question

You are frying fishes on a pan which can accommodate only 2 fishes at one time. It takes 5 minutes to fry one side of the fish.

What is the shortest time in which you can fry 3 fishes in the same pan ?

Infosys IQ Interview Question

15 minutes.

Put 2 fishes in the pan. Fry for 5 minutes and then take out one and turn the other one. Also put in the third fish. Now fry for 5 minutes. The fish that you turned must be ready now so take it off while turning the other one. Also put in the fish which was fried from one side only in the pan. Fry them for 5 minutes and all the three fishes are fried now.

#399 - Linear Thinking Riddle

There are four people in a house. A fireman, an athlete, an old woman and a drunk guy. The house catches fire and before the fact is known, it is too late. All they know is that the entire house is in flames and it will collapse exactly after twelve minutes. Now they can move out of the house but for that, they will have to pass the hallway which is entirely blazing with flames. Thus to move, one must carry a fire extinguisher to keep the flames away. Seeking the burnt wooden floor, only two person can run through that hallway at one time. But for others to go, one must return back with the fire extinguisher. The fireman, is trained for such tasks and can run through the hallway in a minute. The athlete can make it in a couple of minutes. The old woman can run slowly and will cover the hallway in four minutes. The drunk guy will take five minutes to run through it. If all of them can make it through the hallway in twelve minutes, all of them will be saved. When two move together, they will run with the speed of the slower one.

How will all four of them manage to run to safety?

Linear Thinking Riddle

1. Fireman and the fit guy will move first which will take 2 minutes.
2. Fireman will return back with fire extinguisher, taking 1 minutes.
3. Drunk guy will move with old woman taking 5 minutes.
4. The fit guy will return taking 2 minutes.
5. Both the fit guy and fireman will move taking 2 minutes.

2 + 1 + 5 + 2 + 2 = 12 minutes.

#400 - Hardest Riddle Ever Made

Dr. Doom invited a group of puzzle fanatics in a party which was oriented for having puzzle oriented games. At night, he introduced the guests with a 'unique riddle'. A prize was offered for the one who solved it first.

The guests included six people named Tom Paul, Fox Obama, Jeremy Reener, Alex Murphy, Prim Pastor, and Ellen Page. The winner for the 'unique riddle' contest was to be announce after the dinner. So Dr. Doom stood up and started the announcement:

'Okay now everybody!'
'The winner of…'
'The Hardest Riddle Ever Event'

But before he could complete, the light went out and his voice was not heard without the mic by anyone. But they already knew who the winner was. Can you deduce the name of the winner?

Hardest Riddle Ever Made

The winner is Fox Obama.

Just analyze the first three statements of Dr. Doom and see the first alphabets of each word in each line.
O N E
T W O
T H R E E
Thus, the next statement must be the one whose initials are F and O to form FOUR.
Thus it is Fox Obama.
The last sentence must be:
'Fox Obama: Ultimate Riddler!'