#11 - Death Match Riddle

In the Wild West, you are challenged into a death match by two bounty hunters nicknamed Golden Revolver (GR) and Killer Boots (KB). You accept the challenge. None of you want to waste any of the bullet and so a certain rules are laid down:
1) All of you will shoot in a given order till the last man standing.
2) Each of you shoots only once upon his turn.
3) If any one of you is injured, the other two will finish him off with iron rod.
4) The worst shooter of all (which is you) shoots first and the best one shoots at the last.

Now, how will you plan things if you know that you hit every third shot of yours, KB hits every second shot and GR hits every shot ?

Death Match Riddle

The best thing you can do is shooting your first shot in the air.

Suppose if you shoot KB and hit him by luck, you are certainly dead as GR never misses.

If you shoot on GR first and hits him luckily, there is a fifty percent probability that you will die before your next chance.

But if you shoot in the air, KB will definitely shoot on GR as he knows that he is a better shooter. If he misses somehow, then, he is dead and if he hits then, GR is dead.

Now it’s your turn to shoot and you stand a 1/3 chance that you will hit.

This is the best situation you can have. Doing anything else will bring you under worse situation for sure.

#12 - Find The Killer Riddle

A person is found murdered in his office. When the crime scene is investigated, the police finds out that there is a calendar on which the victim has written a few numbers with his blood. The numbers are 4, 11, 11 and 4.

There are four suspects of the murder, Paul, Nina, Anna and Lee. Can you find out who is the murderer?

Find The Killer Riddle

Anna

The numbers written on the calendar actually represents the months in the calendar whose initial letter represents the name of the killer.
4 – April (A)
11 – November (N)
11 – November (N)
4 – April (A)

Thus the killer is Anna.

#13 - Water Gallon Riddle

You have three bowls with you of capacity 8, 5 and 3 liters. The 8 liters bowl is filled completely. Using these three bowls you have to divide the 8 liters in (4 + 4) liters. How can you do it in minimum number of transfers?

Water Gallon Riddle

Fill the 5 liters bowl from the 8 liters bowl.
Take the 5 liters bowl and fill the 3 liters bowl.
Take this 3 liters bowl and empty it inside 8 liters bowl.
Pour the remaining 2 liters from the 5 liters bowl to the 3 liters bowl.
Take the 8 liters bowl and pour it in the 5 liters bowl.
Pour the missing 1 liter from the 5 liter bowl to the 3 liters bowl.
Now there is 4 liters left in the 5 liters bowl.
Now pour 3 liters back from the 3 liters bowl to the 8 liters bowl.

That's it, we now have 4 liters in the 8 liters bowl and 5 liters bowl.

#14 - Directi Interview Logic Aptitude Puzzle

On a certain island, people are gifted with assorted eye colors. There are a hundred green colored and a hundred grey colored pair of eyes. On that island, there is no mirror available. Thus no one knows the eye color of their own. They could have asked each other but that is prohibited. They are not allowed to converse with each other. However, they can study and analyze other's eyes. They don't even know the statistics and so it is believable to them that their eyes can be blue as well. There is a chance of freedom from the island. If anyone is able to guess the color of his own eyes correctly, he will be set free and can leave the island.

On one particular day, an outsider comes to the island and makes an announcement that he has seen someone with grey color eyes. What will happen now?

Directi Interview Logic Aptitude Puzzle

If there is only one person with grey colored eyes, he will see all other people and find out that no one has grey eyes. Thus he will come to know that he himself has grey eyes. Thus, he will leave the island that very day.

If there are two people with grey eyes, they will find only one pair of grey eyes and will think that that is the person with grey eyes. So they both won't leave the island. On the next day however, they will see that no one left the island and they will understand that both of them has the same eye color that is grey color.

Now through induction, since there are 100 people with grey eyes, all of them will leave the island on the 100th day after the announcement was made by the outsider.

#15 - Conditional Probabitlity Riddle Google Interview

A mathematics teacher took exam of his students. Out of the total students, 25% of the students passed both the tests included in the exam. However, only 42% were able to clear the first test.

Can you find out the percentage of those students who passes the first test and also passed the second test ?

60%

Explanation:
This type of questions call in for the application of conditional probability as the question is asking you to find out the probability that the second test was passed with the given situation that the first one was passed.

The formula for conditional probability:
P (Second/First) = P (First and Second)/ P (First)
= 0.25/0.42
=0.60
=60%

#16 - Long Funny Riddle

Once upon a time, there was a bus conductor who was extremely rude to all the passengers. On a certain day, a young and charming lady tried boarding the bus. But he did not stop the bus. As a result, the girl came under the bus and was killed. The agitated passengers took the conductor to the police station. The police took him to the court for trial. In the court, the judge gave him death sentence.

He is then taken to the electrocution chamber. In that room, there is a chair in the center of the room and a banana peel lies just behind the chair. The conductor is strapped to that chair and is being exposed to a high voltage current. But to everyone’s surprise, he is able to survive through the current that is enough to kill two people at once. The judge decides that it is a miracle and sets the conductor free.

The conductor then returns back to his profession. After a few months, a middle aged lady tries to board the bus. The conductor does not stop the bus and as a result the lady gets run over by the bus which kills her on the spot. The agitated passengers take him to the police. The police takes him to the court for the trial. In the court, the judge decides for capital punishment for the conductor.

The conductor is taken to the electrocution chamber again. In that chamber, there is a chair in the middle of the room and a banana peel lies behind the chair. He is strapped to the chair and exposed to a high voltage. To everyone’s surprise, he survives again. Thus, the judge sets him free.

The conductor returns back to his profession. After a few months. An old lady tries to board the bus. The bus conductor after remembering his previous actions, stops the bus. But unfortunately, the old lady slips while climbing up the bus and dies due to his injuries. The passengers take him to the police again. The police takes him back to the court. Though the judge knows that he is not guilty, he sentences him to death knowing his previous record.

The conductor is taken to the electrocution chamber again. He is strapped to the chair in the center of the room behind which, there is a banana peel. He is exposed to the current and this time he is killed instantly.

Why did he die this time and not the previous times?

Long Funny Riddle

He died this time because, he was being a 'Good Conductor'. A good conductor passes through electric current efficiently. While in both the previous cases, he was being a 'Bad Conductor' which is why the current could not pass through him.

#17 - Hardest Probability Problem

If you keep rolling a pair of dice together till a sum of 5 or 7 is obtained, then what is the probability that a sum of 5 comes before a sum of 7?

Hardest Probability Problem

This can be solved in a generic and complex way but let us not go into all that.

There can be four ways through which the pair of dice results in a sum of 5. There can be six ways through which the pair of dice can result in a sum of 7.

Now, we want the probability of the pair of dice resulting in a sum of 5 before a sum of 7. Thus probability = 4/(4+6) = 4/10 or 2/5.

#18 - Logic Riddle For High School

Adam gave half of the apples he had plus one more to Eve. He gave half of the remaining ones plus one more to Diana. Now, Adam was left with just one apple.

Can you find out how many did he have in the beginning?

Logic Riddle For High School

10

In such type of questions we can come to a conclusion by working our way backwards.

He is left with one apple in the end. He gave half of what he had plus one to Diana. If we remove the extra one, the he must have had two apples. Since now both of them have half of the remaining ones, it must be 2 * 2 = 4 apples.

Again move back. Adam gave half of what he had plus one extra to Eve. Thus if we remove that extra one and give it back to Adam, then Adam must have 5 apples. Since he gave half to Eve, it means he must have had 5 * 2 = 10 apples in the beginning.

Thus Adam had 10 apples in the beginning.

#19 - Lateral Thinking Problem

Daniel walks into a movie theater. While in the movie, he suddenly smiles delightfully. About a couple of minutes later, he seems shocked. He walks out of the theater, goes to a bridge and jumps over the edge killing himself.

Why did he do it?

Lateral Thinking Problem

This puzzle can only be solved with lateral thinking, there is no logical reasoning behind it.

Daniel had been the father of two identical twins named Justice and Damien. Ironically, both of them had starkly opposite temperament. While Justice was kind and generous, Damien was quite violent and rude.

On a certain day, Justice approached his father and told him that Damien had killed a man. Daniel rushed to the crime scene with Justice and saw Damien huddled over a dead man. Rage took Daniel over and he started fighting with his son eventually killing him accidentally. When the police reached the crime scene, he arrested Daniel and he was put in prison for ten years. He received a note from Justice while he was in prison in the very first month. The note said that Justice could never forgive his father for what he did with Damien and that he will never see him again.

After moving out of the prison, Daniel came to know that Justice had become a junior film star. He also came to know that a film starring him in a minor role was running in the theater. He quickly bought the ticket to the nearest theater and went inside the hall filled with excitement. When he saw Justice on the silver screen, he could not help but smile feeling proud of his son. But soon after the camera zoomed over the back of his neck and he saw a birthmark that belonged to Damien.

He understood that in reality, Damien had killed the man and the one whom he father took as Damien was actually Justice trying to save the man. He is shocked at the revelation and struck with grief. Thus he decides to kill himself by jumping from the bridge.

#20 - Short Logic Maths Puzzle

Calculate the number of degree between the hour hand and the minute hand of an analogue clock that is displaying a time of 3:15 at present.

Short Logic Maths Puzzle

This question can be a bit tricky. But if you pay attention, you can solve it. When fifteen minutes have passed after three, the hour hand must have moved exactly one fourth of an hour. Thus both the hands will make an angle of 7.5 degree between them.