What is the fastest way to double your money?

Can you find the missing number in the third row?
35 20 14
27 12 18
5 2 ?

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 "?".

A new Engineering building containing 100 offices had just been completed. John was hired to paint the numbers 1 to 100 on the doors. How many times will John have to paint the number nine (9)?

I am a five-letter word and comprises two different vowels and three same consonants. I am so strong that I can spoil your entire work.

Can you find out who am I?

John can place six large boxes or nine small boxes into a carton.

Can you find out in how many cartons can he place sixty-six boxes in total?

Can you count the number of quadrilaterals in the picture below?

I know a country, If you remove the last alphabet of its name, it will become a part of your body. Do you name it?

A boy was at a carnival and went to a booth where a man said to the boy, "If I write your exact weight on this piece of paper then you have to give me $50, but if I cannot, I will pay you $50." The boy looked around and saw no scale so he agrees, thinking no matter what the carny writes he'll just say he weighs more or less. In the end the boy ended up paying the man $50. How did the man win the bet?

What does the below mathematical rebus mean?