Replace the question mark with the number below given a simple math problem.

Kohli and Dhoni decided to have a paintball match.
Kohli told Dhoni, "Sir it is not right as you got thrice the paintballs I have".

Dhoni instantly gives Kohli 10 hit paintballs.
Kohli replied, "Sir, I believe you still have twice the paintballs than I have".

Dhoni gives "?" more paintballs to Kohli.
Kohli replied, "Sir it is even now, Let us have a match".

What is "?".

With pointed fangs I sit and wait; with piercing force I crunch out fate; grabbing victims, proclaiming might; physically joining with a single bite. What am I?

One is to three as three is to five and five is to four and four is the magic number.
What is the pattern?

Prove that twice of ten is the same as twice of eleven.

Which tank will fill first?

What is the fastest way to double your money?

Why is Saturday stronger than Monday?

The sum of a mother, her baby and her dog's weight is 170 Kg. How much does the baby weigh if the mother weighs 100 kg more than the combined weight of the baby and the dog, and the dog weighs 60 per cent less than the baby?

If there are fifteen crows on a fence and the farmer shoots a third of them, how many crows are left?