Solution:

Velma waits until night time and then goes through the second door.

(No sun at night)

Solution:

Place 1 white marble in one bowl, and place the rest of the marbles in the other bowl (49 whites, and 50 blacks).

This way you begin with a 50/50 chance of choosing the bowl with just one white marble, therefore life! BUT even if you choose the other bowl, you still have ALMOST a 50/50 chance at picking one of the 49 white marbles.

Solution:

The mathematician made a small fence around himself and declared himself to be on the outside.

Solution:

Brian is the one who speaks truth.

Adam is lying about Brian. Also Cody Is lying since Brian does not lie. Thus Brian is the one speaking truth. Any other combination will fail to come out true.

Solution:

This is what Birbal said after bowing in front of the real king:
"Your majesty, the other kings were watching you closely in order to imitate you accurately while you were sitting with your calm and composed demeanor. This is how I found out that you are the real king."

His Quick wit flabbergasted the king and he was rewarded with luxurious gifts and jewels in return.

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:

That was a women's football world cup. They had strict rules against female nudity in their country and thus the players were arrested.

Solution:

Birbal wrote - "This time will pass soon."

When read in good time, you will feel sad. However, it is essential to keep the fact in the mind. Thus, do not be haughty and keep doing the good work for society.

When read in bad time, you will feel optimistic and get a morale boost that with your hard work you can change the situation.

Solution:

The man said, 'I will be killed by giving poison.'

If Akbar says the statement is true, the man will be killed by hanging which will make his statement false.
If Akbar says the statement is false, the man will be killed by giving poison which will make the statement true.

Thus Akbar had no choice but to leave the man unpunished.

Solution:

'Didn't you say that you sold your well to this farmer?' Birbal asked the neighbour. 'So, the well belongs to him now, but you have kept your water in his well. Is that right? Well, in that case you will have to pay him a rent or take your water out at once.'
The neighbour realized that he was outwitted. He quickly apologised and gave up his claim.