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- Question :: 1
**Lazy people need to be smart**Four glasses are placed on the corners of a square Lazy Susan (a square plate which can rotate about its center). Some of the glasses are upright (up) and some upside-down (down).

A blindfolded person is seated next to the Lazy Susan and is required to re-arrange the glasses so that they are all up or all down, either arrangement being acceptable (which will be signaled by say ringing of a bell).

The glasses may be rearranged in turns with the subject to the following rules: Any two glasses may be inspected in one turn and after feeling their orientation the person may reverse the orientation of either, neither or both glasses. After each turn, the Lazy Susan is rotated through a random angle.

The puzzle is to devise an algorithm which allows the blindfolded person to ensure that all glasses have the same orientation (either up or down) in a finite number of turns. (The algorithm must be deterministic, i.e. non-probabilistic )

No Best Answer on this question yet!

**Asked In :**

Alcatel-Lucent - Question :: 2
**These kids deserve medals**There are 10 incredibly smart boys at school: A, B, C, D, E, F, G, H, I and Sam. They run into class laughing at 8:58 am, just two minutes before the playtime ends and are stopped by a stern looking teacher: Mr. Rabbit.

Mr. Rabbit sees that A, B, C, and D have mud on their faces. He, being a teacher who thinks that his viewpoint is always correct and acts only to enforce rules rather than thinking about the world that should be, lashes out at the poor kids.

“Silence!”, he shouts. “Nobody will talk. All of you who have mud on your faces, get out of the class!”. The kids look at each other. Each kid could see whether the other kids had mud on their faces, but could not see his own face. Nobody goes out of the class.

“I said, all of you who have mud on your faces, get out of the class!”

Still, nobody leaves. After trying 5 more times, the bell rings at 9 and Mr. Rabbit exasperatedly yells: “I can clearly see that at least one of you kids has mud on his face!”.

The kid's grin, knowing that their ordeal will be over soon. Sure enough, after a few more times bawling of “All of you who have mud on your faces, get out of the class!”, A, B, C, and D walk out of the class.

Explain how A, B, C, and D knew that they had mud on their faces. What made the kids grin? Everybody knew that there was at least one kid with mud on his face. Support with a logical statement that a kid did not know before Mr. Rabbit’s exasperated yell at 9, but that the kid knew right after it.

No Best Answer on this question yet!

Not Yet Asked in Any of the Companies

- Question :: 3
**All men must die**One day, an alien comes to Earth. Every day, each alien does one of four things, each with equal probability to:

(i) Kill himself

(ii) Do nothing

(iii) Split himself into two aliens (while killing himself)

(iv) split himself into three aliens (while killing himself)What is the probability that the alien species eventually dies out entirely?

No Best Answer on this question yet!

Not Yet Asked in Any of the Companies

- Question :: 4
# Chameleons go on a date

On an island live 13 purple, 15 yellow and 17 maroon chameleons. When two chameleons of different colors meet, they both change into the third color. Is there a sequence of pairwise meetings after which all chameleons have the same color?

- Question :: 5
# The Man in the Elevator

A man lives on the tenth floor of a building. Every day he takes the elevator to go down to the ground floor to go to work or to go shopping. When he returns he takes the elevator to the seventh floor and walks up the stairs to reach his apartment on the tenth floor. On a rainy day, or if there are other people in the elevator, he goes to his floor directly. He hates walking so why does he do it?

This is probably the best known and most celebrated of all lateral thinking puzzles. It is a true classic. Although there are many possible solutions which fit the initial conditions, only the canonical answer is truly satisfying.

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