Solution:

He simply suggested that one of the brothers will be allowed to divide the land but he must take into consideration that it will be the other one who will have a choice of selecting his land between the two halves first.

Thus both will be happy in such manner.

Solution:

There is only one possible shape i.e. a cone.

Solution:

204

Solution:

If they are standing back to back, then it is possible.

Solution:

Tilt the barrel until the fruit juice barely touches the lip of the barrel. If the bottom of the barrel is visible then it is less than half full.If the barrel bottom is still completely covered by the fruit juice, then it is more than half full.

Solution:

The last marble will be yellow.

Since marbles can only be taken out in pairs and you started off with an odd number of yellows there is always going to be one yellow left over that you'll keep putting back in the box until it's left on it's own.

Solution:

Silence

Solution:

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.

Solution:

Bob hacked the server.

You can solve this mystery by assuming every one of them as a hacker turn wise. Suppose Timothy is the hacker. Then, his first and last statement will be lies. But that cant be true as he can speak just one lie.

You will find the same result while assuming Christopher, Maggie and Beatrice as the hackers but will see that while assuming Bob as the hacker, only his first statement is false.

Thus Bob is the hacker.

Solution:

If you know a bit of science, you must be knowing that this expression equals gravity. So the name of the movie is - Gravity.