Aeroplane..(Microsoft puzzle)

Riddle:
The puzzle question is : On Bagshot Island, there is an airport. The airport is the homebase of an unlimited number of identical airplanes. Each airplane has a fuel capacity to allow it to fly exactly 1/2 way around the world, along a great circle. The planes have the ability to refuel in flight without loss of speed or spillage of fuel. Though the fuel is unlimited, the island is the only source of fuel.

Rectangle 8 part puzzle

Question:

We have a rectangle
It is divided in eight parts by three vertical and one horizontal line so that there are 8 chambers.
Now we have numbers from 1-8 to be filled in these chambers.
Rule : No two consecutive numbers must be present either side to side or diagonal
Invalid situation example
Given 5 at position 2 then 4 cannot occur at any of the give position.

Minimum no. of rats needed for finding poison in bottle....google puzzle

Question:
There are 8 bottles, one has poison. What's the minimum number of rats you need to find the poison bottle in time T, and how? (You get the rats you need all at once, feed them all at the same time, and poison kills them after time T.)

prove that n(n2-1) is div by 24...amazon puzzle

Question:

prove that n(n2-1) is div by 24

Note: n is odd and >=3

Solution:

N(N^2-1)=(N-1)N(N+1)
means it must be divisible by 2 and 3

Solution:Weight difference puzzle....morgan stanley logical puzzle

Solution:

I believe the solution is as follows (assume initial configuration to be an empty bucket at the top and a bucket with the stone in it at the bottom):

1. Prince goes down, rock goes up.
2. Queen goes down, Prince goes up.
3. (the rock is dropped from the top of the tower)

Weight difference puzzle....morgan stanley logical puzzle

Question:
There are 3 people on a tower which may collapse due to fire. King(78 kg),Queen(42kg) and Prince(36kg).There is a pulley on the tower with baskets tied to it on both the sides of rope around the pulley. There is a 30kg stone in one of the baskets. 

Probability of rolling a 10 and an 11 before rolling a 7?

Question:
What is the probability of rolling a 10 and an 11 before rolling a 7?

Solution: Toggling of 100 switches..

Solution:

This is a little tricky. Say switches nos are 1 to 100.
Here
after 1st round, all switches are ON (All were OFF, so toggling will make all ON)
after 2nd round, all switches divisible by 2 (switch no divisible by 2) are TOGGLED
after 3rd round, all switches divisible by 3 (switch no divisible by 3) are TOGGLED
after 4th round, all switches divisible by 4 (switch no divisible by 4) are TOGGLED
.......

Toggling of 100 switches..

Question:
Suppose there are 100 lights, which are all off. First round past them, turn all on;
Second round past, turn every other off;
Third round, turn every third on;
vice verse;
Ask the 100 round past, which light will be on?

Probability of rolling a 10 and an 11 before rolling a 7

Question:
What is the probability of rolling a 10 and an 11 before rolling a 7?

Solution: Maximum no. of matches puzzle

Solution:
56 points are distributed to 8 team. In the worst case, team0 loses all the games, he gets 0 point. team1 win two games with team0 and loses all other games, he gets 2 points.

Maximum no. of matches puzzle

Question:
Consider a series in which 8 teams are participating. each team plays twice with all other teams. 4 of them will go to the semi final.How many matches should a team win, so that it will ensure that it will go to semi finals.?

Minimum no. of queens in chess board

Question:
Imagine there are infinite number of Queens (Chess Game Piece) with u. Find the minimum number of queens required so that every square grid on the chess board is under the attack of a queen. Arrange this minimum no. of Queens on a chess board.

Solution:Amazon puzzle: find probability of men to go in room

Solution:

1 - 1/2 * 1/2 * 1/2 * 1/2 =>  15/16

explanation:

It is the combined probability of all possible events minus the probability that all four people will NOT open the door (1/2)^4. Another way to look at this problem would be to take the sum of the probabilities of all possible ways that the door will be opened:

Amazon puzzle: find probability of men to go in room

Question:
There are 4 people in a closed room and you are waiting outside to enter into the room. You can enter only when one of them opens the door. The probability that somebody will open the door is 1/2. Now what is the probability that the door will be opened so that you can go inside?

Solution:Find average salary without knowing other`s salary

Solution:

Lets name these employees A, B, C and D

1. A chooses any random value and whispers it to B privately
2. B chooses any random value and whispers it to C privately
3. C chooses any random value and whispers it to D privately
4. D chooses any random value and whispers to to A privately

Find average salary without knowing other`s salary

Question:
How can four employees calculate the average of their salaries without knowing other's salary?

Solution:Distance between 2 poles...amazon puzzle

Solution:
The distance between poles is zero. In this case, the cable will be hanging directly down and its center be 8mts down which is half of its length.

Distance between 2 poles...amazon puzzle

Question:

There are two poles of equal height 15mts. One cable with length 16mts is hanging between that two poles. The height from center of the cable to earth is 7mts then what is the distance between that two poles.

Solution: Arrange numbers 1-8 in 2X4 matrix with no consecutive...Adobe puzzle

Solution:

1. keep no. in group of two alternate numbers.
{1,3} {2,4} {5,7} {6,8}

2.now fill the center 4 block with two group containing first and last number.
(1,3) {6,8}

Arrange numbers 1-8 in 2X4 matrix with no consecutive...Adobe puzzle

Question:
There is a 2X4 matrix, in this you are supposed to arrange the numbers from 1-8, so that no consecutive numbers are adjacent(vertically, horizontally and diagonally) to each other. It is possible to do if one keeps on trying it randomly

Solution: Find no. of acute traingle from cube having 8 vertices

Solution:
Acute angled triangle can be formed by connecting the diagonal of three adjacent faces of the cube.
The number of ways three adjacent faces can be chosen is (6x4x2)/(3x2x1) = 8
So the total number of acute angled triangle is 8.

POST YOUR OPINION IF YOU HAVE BETTER SOLUTION

Find no. of acute traingle from cube having 8 vertices

Question:
Think of the 8 vertices of a given cube. You are allowed to join three
vertices to form a triangle. How many such unique acute triangles can you
make ??

Solution of 6 litre from 7 & 4 litre

Solution:
1. Fill 7 liter tumbler fully: 7 - 0
2. Fill 4 liter tumbler fully by pouring from the 7 liter one: 3 - 4
3. Empty the small one: 3 - 0

6 litre from 7 & 4 litre

Question:
There are two tumblers one 7 litre tumbler, one 4 litre tumber and ample water. Get 6 liters of water in 7 litre tumbler.

Solution of Bridge crossing Riddle

Solution:
-> 1. + 2. - 2 min
<- 1. - 1 min
-> 3. + 4. - 9 min
<- 2. - 2 min
-> 1. + 2. - 2 min

Bridge crossing Riddle

Question:
There are four people at the end of bridge. They take following time to cross the bridge:
1st: 1 min
2nd: 2 min
3rd: 7 min
4th: 9 min

Solution of Burn the rope....good puzzle

Solution:
Take 2 ropes R1, R2. Light R1 at both ends and R2 at one end. When R1 is completely burned (30 minutes have passed), light R2 at the other end. When R2 is completely burned 45 minutes have passed.

POST YOUR OPINION IF YOU HAVE BETTER SOLUTION

Burn the rope....good puzzle

Question:
there are unlimited ropes of same length and if we burn them it will take 1 hour.
How to measure 45 mins?

Solution of 100 door puzzle....microsoft interview puzzle

Solution:

This problem is designed to seem overwhelming. You don’t have time to draw a diagram of 100 lockers and count 100 passes through them. Even if you did, solving the problem that way wouldn’t illustrate any skill or intuition, so there must be some trick that can be used to determine how many doors will be open. You just have to figure out what that trick is.

It’s unlikely that you’re going to be able to intuit the solution to this problem by just staring at it. What can you do? Although it’s not practical to solve the entire problem by brute force, solving a few lockers in this manner is reasonable. Perhaps you’ll notice some patterns you can apply to the larger problem.

Solution of 2 Egg Problem: Google Interview Puzzle

Solution:

Drop the first egg from 50.If it breaks you can try the same approach for a 50-storey building (1 to 49) and try it from 25th floor. If it did not break try at 75th floor. And use linear search with the remaining portion of storey we need to test. For example if the first egg breaks at 50 we need to try all possibilities from 1 to 49.

Solution of Village of demons & sleeping man puzzle....tricky puzzle

Solution:

1 demon 1 human
demon eat human.
2 demon 1 human
nothing happens.

Village of demons & sleeping man puzzle....tricky puzzle

Question:

given a village with demons and a sleeping man, The man is always sleeping ,never wakes up. Now a demon can eat the sleeping man , but after that
he will fall asleep , any demon can eat another sleeping demon.

Find bad apples from boxes in 1 attempt...!!!

Question:
There are 10 boxes of apples. Each apple in the boxes weights 1 pound, except that one of the boxes contains bad apples, which weights 0.9 pound each. You are given a digital weight (not a scale), and you can take apples out of the boxes. what is the minimum time of weighs to find out which box has bad apples?

Move block in matrix

Question:
Given a m*n matrix and a person is sitting in (0,0) box, and he has to go to the (m-1,n-1) box of the matrix .And the person can only go to right or down box from its current box position . We need to find out the number of ways he can reach from start to destination box .

100 prisoner`s hat problem..

Question:
There are 100 prisoners , and a officer of them . Now the officer gave the command to the prisoner that next day they will be going to wear a hat which they will not be know its colour . But its colour will be either Red or Blue . And he says that all the prisoner will be standing in a line .

Google letter/number series puzzle

Question:

Fill in the blanks:

--   --  --  H  I   K  L   M   N  T
     --   --  --  G  J  O  P  Q   R  S

Answer:

hint:Characters in the top row are written with straight lines, whereas those in the bottom row are written with curved lines.

1) This pattern perfectly fits with the first 6 characters.
A E F
B C D

2) b c f

a d e

find random number between 1-7

Question:
Given a random number generator say r(5) generates number between 1-5 uniformly at random , use it to in r(7) which should generate a random number between 1-7 uniformly at random.

17 min bridge crossing puzzle

Question:
There are four people who want to cross a bridge; they all begin on the same side. You have 17 minutes to get them all across to the other side. It is night, and they have one flashlight. A maximum of two people can cross the bridge at one time. Any party that crosses, either one or two people, must have the flashlight with them.

9 card puzzle

Question:
9 cards are there. u have to arrange them in a 3*3 matrix.
cards are of 4 colors.they are red,yellow,blue,green.
conditions for arrangement: one red card must be in first row
or second row.2 green cards should be in 3rd column.Yellow
cards must be in the 3 corners only. Two blue cards must be in
the 2nd row. Atleast one green card in each row.

100 door puzzle....microsoft interview puzzle

Question:
Lets say you have a room with 100 doors in it. Initially, all of these doors are open. You have 100 people that will be entering the room. The 1st person toggles every door, 2nd person toggles every other door, 3rd toggles every 3rd door, ... , nth person toggles every nth door. How would you determine the state of all 100 doors after all 100 people have entered the room?

Solution:
CLICK HERE

POST YOUR OPINION IF YOU HAVE BETTER SOLUTION

1000 barrels Puzzle

Question:
A king is about to give a party in 24 hours. For the party they have arranged drinks which will be served through 1000 barrels. Out of jealousy , some one near to king has poisoned one of the barrels. The poison is so strong that even a drop can kill a person. But results are not immediate. A person may die from 13 to 20 hrs. Now king has a duty of finding that barrel. He has 24 hours with him. And he has unlimited prisoners on which the drinks can be tested. Find out the maximum prisoners he would need to find out that barrel.

2 dice puzzle

Question:
You are given 2 dice. Both are fair. One of the dice has no numbers printed on it. You have to label the unmarked dice such that when both the dice are thrown, the sum on the faces is evenly distributed between 1 and 12.

count the number of students in a classroom in quickest way

Question:

How will you count the number of students in a classroom in quickest possible manner.

Find shortest path in an array

Question:
Given a character array. Find if there exists a path from O to X. Here is an example

. . . . . . .
. . . . . . .
w . . . . . .
w .w.w..
. . . . O . .
. . w. . . .
. . . X . . .

2,4,8,16,24...?

Question:
What is the next number in the series
2,4,8,16,24...

Obtain 4 litre from 5 & 3 litre jar

Question:
There are 2 jars 5 lit and 3 lit capacity
measure 4 lit using them

3black and 2 white cap tricky puzzle

Question:
3 black caps and 2 white caps
randomly 3 caps are chosen and A,B,C are made to wear
they are standing in que and A can see B nC , B can only see C and C cant see anyone
A is asked which cap are you wearing? Ans from A was he dont knw
B was asked which cap is he wearing? B answered I dont know
But when asked C , he gave the correct answer
The question was...which color cap was C wearing?

Find top 5 horse from 25 horses

Question:

how to find top 5 horses from 25 if there are only 5 lanes.In min no. of races?

8 ball puzzle..to select lighter ball from them

Question:
Just Example : "Given 8 cue balls , one is weighing lesser than other 7. Find that(light weight) ball using just 2 chances on balance weight."

How to find a general solution to these kind of question? How to divide this set of balls? Is there any finer method or general formula?

8 ball puzzle select heavier from them....

Question:

You have eight balls all of the same size. 6 of them weigh the same, and two of them weighs slightly more. How can you find the balls that is heavier by using a balance and do this in minimum number of steps?