Polar bear puzzle

Puzzle:

There is a house with four walls. Each wall faces south. There is a window in each wall.

A bear walks by one of the windows. What colour is the bear?

Solution:
White. If all the walls face south, the house is at the north pole, and the bear, therefore, is a polar bear.

Solution of Bridge crossing Riddle

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

Total - 16 min
note:
-> forward direction
<- Reverse direction

POST YOUR OPINION IF YOU HAVE BETTER SOLUTION

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

Condition: 
1. They have only one torch and they can't cross bridge without torch.
2. and only 2 person can cross bridge at a time.

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.
Start by choosing an arbitrary locker, 12, and determining whether it will end open or closed. On which passes will you toggle locker 12? Obviously on the first pass, when you toggle every locker, and on the twelfth pass when you start with 12. You don’t need to consider any pass after 12 because those will all start farther down the hall. This leaves passes 2 through 11. You can count these out: 2, 4, 6, 8, 10, 12 (you toggle on pass 2); 3, 6, 9, 12 (on 3); 4, 8, 12 (on 4); 5, 10, 15 (not on 5); 6, 12 (on 6); 7, 14 (not on 7), and so on. Somewhere in the middle of this process, you will probably notice that you toggle locker 12 only when the number of the pass you’re on is a factor of 12. If you think about this, it makes sense: When counting by n, you hit 12 only when some integer number of n’s add to 12, which is another way of saying that n is a factor of 12. Though it seems simple in retrospect, this probably wasn’t obvious before you worked out an example.

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.

Now this looks a feasible solution. In computer student's jargon do a binary search with first egg and linear search with the second one. Best case is log (100) and worst is 50.

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

Solution:

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

3 demon 1 human
one demon eat the human.
Explanation:
if there are odd number of eaters and one sleeping target, one of the eater(demon) will eat the target(sleeping demon/man).

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.

If demons are very smart and would always choose to stay alive than to eat the man and risk their lives.
so if initially there are 65 demons and 1 sleeping man .. what would happen in the village ??

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?

Solution:

it's simple:
take 1 apple from box 1, 2 apples from box 2 ... 10 apples from box 10

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 .
And then the officer will start asking the color of the prisoner one by one from the back . whichever prisoner says the wrong color of his hat ,gets shoot .So now we have to find out wat strategy should the prisoners should apply to safe maximum prisoners .

Google letter/number series puzzle

Puzzle:

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

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

Puzzle:
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.
The flashlight must be walked back and forth; it cannot be thrown, for example. Person 1 takes 1 minute to cross the bridge, person 2 takes 2 minutes, person 3 takes 5 minutes, and person 4 takes 10 minutes. A pair must walk together at the rate of the slower person’s pace. For example, if person 1 and person 4 walk across first, 10 minutes have elapsed when they get to the other side of the bridge. If person 4 returns the flashlight, a total of 20 minutes have passed and you have failed the mission.

What are your weaknesses? (HR interview)

TRAPS:  Beware - this is an eliminator question, designed to shorten the candidate list. Any admission of a weakness or fault will earn you an “A” for honesty, but an “F” for the interview.

PASSABLE ANSWER:  

Disguise a strength as a weakness.

Example: “I sometimes push my people too hard.  I like to work with a sense of urgency and everyone is not always on the same wavelength.”

Drawback:  This strategy is better than admitting a flaw, but it's so widely used, it is transparent to any experienced interviewer.

What are your greatest strengths? (HR interview)

TRAPS:  This question seems like a softball lob, but be prepared. You don't want to come across as egotistical or arrogant. Neither is this a time to be humble.

BEST ANSWER:  You know that your key strategy is to first uncover your interviewer's greatest wants and needs before you answer questions. And from Question 1, you know how to do this.

Prior to any interview, you should have a list mentally prepared of your greatest strengths. You should also have, a specific example or two, which illustrates each strength, an example chosen from your most recent and most impressive achievements.

Tell me about yourself (HR interview)

TRAPS:  Beware, about 80% of all interviews begin with this “innocent” question. Many candidates, unprepared for the question, skewer themselves by rambling, recapping their life story, delving into ancient work history or personal matters.

BEST ANSWER:  

Start with the present and tell why you are well qualified for the position. Remember that the key to all successful interviewing is to match your qualifications to what the interviewer is looking for. In other words you must sell what the buyer is buying. This is the single most important strategy in job hunting.

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?