### #1 - Adobe Cool Logical Interview Puzzle

Suppose you are sitting in an interview and the interviewee asks you an aptitude question.

You have three buckets with capacity 4 liters, 8 liters and 10 liters and you have a large tank of water. Now you have to measure 3 liters of water precisely using those buckets. How will you do it?

It is impossible. The reason is that we are asked to measure 3 liters which is an odd number but the buckets we have can contain even liters of water only (4, 8 and 10). If you hoped to fill any of the bucket half, you will not be precise in measurement.

### #2 - Unsolvable Riddle

In a contest, four fruits (an apple, a banana, an orange, and a pear) have been placed in four closed boxes (one fruit per box). People may guess which fruit is in which box. 123 people participate in the contest. When the boxes are opened, it turns out that 43 people have guessed none of the fruits correctly, 39 people have guessed one fruit correctly, and 31 people have guessed two fruits correctly.
How many people have guessed three fruits correctly, and how many people have guessed four fruits correctly

It is not possible to guess only three fruits correctly: the fourth fruit is then correct too! So nobody has guessed three fruits correctly and 123-43-39-31 = 10 people have guessed four fruits correctly.

### #3 - Paradox Brain Teaser

The following sentence is false. The preceding sentence is true.
Are these two sentences true or false?

They are neither. It is a paradox.For first to be true, second must be false which makes the first false as well. Thus it does not work.

### #4 - Impossible Maths Number Riddle

We know that the number 7 is the prime followed by a cube. Which next number is also a prime followed by a cube ?

There is no number other than 7 that is a prime followed by a cube.
To prove, let us assume that n3-1 is a prime for n.
N2-1 = (n^1)(n2+n+1)
Now, n-1 divides n3-1.
If n-1>1, then we are done as it is a contradiction to n3-1 being a prime.

### #5 - Worlds Best Paradox Riddle

Outside a tattoo artist's shop there was a signboard which read 'I make tattoos on only them who do not tattoo themselves'.

Reading it what do you think, does the tattoo artist tattoo himself ?

Well this is a paradox sentence which does not have any specific answer.

### #6 - Tricky Maths Problem

I drive at an average speed of 30 miles per hour to the railroad station each morning and just catch my train. On a particular morning there was a lot of traffic and at the halfway point I found I had averaged only 15 miles per hour. How fast must I drive for the rest of the way to catch my train?

The train is just about to leave the station and there is no way I will be able to catch it this time.

### #7 - Paradox Probability Puzzle

This is a famous paradox which has caused a great deal of argument and disbelief from many who cannot accept the correct answer. Four balls are placed in a hat. One is white, one is blue and the other two are red. The bag is shaken and someone draws two balls from the hat. He looks at the two balls and announces that at least one of them is red. What are the chances that the other ball he has drawn out is also red?

There are six possible pairings of the two balls withdrawn, RED+RED, RED+WHITE, WHITE+RED, RED+BLUE, BLUE+RED, WHITE+BLUE. We know that the WHITE + BLUE combination has not been drawn. This leaves five possible combinations remaining. Therefore the chances that the RED + RED pairing has been drawn are 1 in 5. Many people cannot accept that the solution is not 1 in 3, and of course it would be, if the balls had been drawn out separately and the color of the first ball announced as red before the second had been drawn out. However, as both balls had been drawn together, and then the color of one of the balls announced, then the above solution, 1 in 5, must be the correct one.

### #8 - Impossible Riddle To Solve

If this sentence is not true then I can fly like superman.

As per the above sentence, can I fly like superman ?

There is no answer to this question as it is a paradox.

### #9 - Oracle Probability Interview Question

What is the probability of choosing the correct answer at random from the options below.

a) 1/4
b) 1/2
c) 1
d) 1/4

If the answer is 1/4, then because 2 out of 4 answer choices are '1/4', the answer must actually be 1/2. This is a contradiction. So the answer cannot be 1/4.
If the answer is 1/2 (or 1), then because 1/2 (or 1) is 1 out of 4 answer choices, the answer must be 1/4. This is again a contradiction. So the answer cannot be 1/2 (nor 1).

So none of the provided answer choices are correct. Therefore the probability of choosing the correct answer is 0%

### #10 - Dream Riddle

Two brothers were watching a horror film on video late one night. One brother dozed off and dreamed that he was being chased by the crazy man from the movie, who was trying to kill him. In the dream, he hid in a cupboard. There was no sound except his heart pounding, and he had no idea where his crazed captor was. He was terrified! At that moment, the video finished, and his brother put his hand on the shoulder of his sleeping sibling to wake him. The shock at that tense moment was enough that the sleeping brother suffered a massive heart attack and died instantly. True or false?

False- if he had instantly died, how would anybody know his dream