In the morning, the monster will line up all the people - single file so that the last person sees the remaining 9, the next person sees the remaining 8, and so on until the first person that obviously sees no one in front of himself. The monster will then place black or white hats on their heads randomly (they can be all white, all black or any combination thereof).

The monster will offer each person starting with the last one (who sees everyone else's hats) to guess the color of his/her own hat. The answer can only be one word: "white" or "black". The monster will eat him on the spot if he guessed wrong, and will leave him alive if he guessed right. All the remaining people will hear both the guess and the outcome of the guess. The monster will then go on to the next to last person (who only sees 8 people), and so on until the end.

The monster gives them the whole night to think.

The Task:

Devise the optimal strategy that these poor natives could use to maximize their survival rate.

Assumptions:

1) All the 10 people can easily understand your strategy, and will execute it with perfect precision.

2) If the monster suspects that any of the people are giving away information to any of the remaining team members by intonation of words when answering, or any other signs, or by touch, he will eat everyone.

3) The only allowed response is a short, unemotional "white" or "black".

4) Having said that, I will add that you can put any value you like into each of these words. For example, "white" can mean "my mother did my laundry" and "black" can mean the guy in front of me is wearing a black hat.

Check Braingle.com for the answer. ]]>

1) They are infinitely logical, smart, and completely aware of their surroundings.

2) They can survive by just eating grass (and there is an infinite amount of grass on the island).

3) They prefer of course to eat sheep.

4) Their only food options are grass or sheep.

Now, here's the kicker:

5) If a lion eats a sheep he TURNS into a sheep (and could then be eaten by other lions).

6) A lion would rather eat grass all his life than be eaten by another lion (after he turned into a sheep).

Assumptions:

1) Assume that one lion is closest to the sheep and will get to it before all others. Assume that there is never an issue with who gets to the sheep first. The issue is whether the first lion will get eaten by other lions afterwards or not.

2) The sheep cannot get away from the lion if the lion decides to eat it.

3) Do not assume anything that hasn't been stated above.

So now the question:

Will that one sheep get eaten or not and why?

Check Braingle.com for the answer. ]]>

-Two 8-liter jugs, filled with water

-One 3-liter jug, empty

-Four infinite size, empty pools

Here's what your objective is:

Fill each of the four pools with exactly 4 liters of water.

Here are your constraints:

-You have nothing else at your disposal.

-There is no other water aside from the two 8-liter water filled jugs.

-Once water is poured into any of the 4 pools it cannot be removed from there.

-The jugs are not symmetric so you cannot measure amount by eye or judge based on shape.

Check Braingle.com for the answer. ]]>