Imagine you are in a room with no windows or doors. How will you get out?

Solve the below puzzle by replacing the question mark with the correct number.

3 6 12

4 8 16

5 10 ?

I am taken from a mine and shut up in a wooden case, from which I am never released, and yet I am used by almost every person. What am I?

I want to fill my bucket using both cold and hot water.
I have two taps for both cold and hot water. The hot water tap fills the bucket in exact 6 hours and the cold water tap fills the bucket in exact 4 hours.
I turn both of them simultaneously but I forgot to turn off another tap which removes the water out of the bucket. This tap can empty the bucket in 12 hours.

How Long will it take to fill the bucket?

What can go through glass without breaking it?

Identify the 10 differences between the two given pictures.

In the picture given below, can you find out which digit will take place of the question mark?

What are the 50th, 63rd and 100th numbers in the sequence below?
4, 5, 8, 8, 9, 9, 12, 13, 13, 13, 17, 18, ...

I am an eight letter word and I am a computer terminology.
The second, third and fourth letters make an animal.
The fourth, fifth, sixth, seventh and eighth letters make a weapon.
The first, second, third and fourth letters can be taken as an outcome of any exam.
The fifth, sixth, seventh and eighth letter combine to form a high end typing software.

Can you tell who am I ?

He does not have any heart but still, He manages to live.
If you kill him, you will eventually die but yet you kill him.
He cannot run, who is He?