I have no doors but I have keys, I have no rooms but I have space, you can enter but you can’t leave! What am I?

You may enter, but you may not come in. I have space, but no room. I have keys, but open no lock. What am I?

It has a long neck, A name of a bird, Feeds on cargo of ships, It's not alive,

What is it?

What jumps when it walks and sits when it stands?

Below, you will find the mathematical proof that 10 equals 9.99999?. But is that possible or there is something wrong about it? Can you find the error?

x = 9.999999...
10x = 99.999999...
10x - x = 90
9x = 90
x = 10

You have a 12 liters jug full of water. You have two empty 8 liters and 5 liters jug. How can you divide the water into two equal parts using these jugs?

What Time Should the last watch show in the below figure?

A man walked into a pub and went straight towards the Barman. He asked for a dirty martini from the Barman. The Barman thought something and then pulled out a pistol from his drawer and aimed it directly at the man. Why did he do that?

No matter how little or how much you use me, you change me every month. What am I?

Open a Laptop which is password protected. Hint for the password is given as below:

1 mobile 3 books 2 Boards 1 night 4 balls 2 lighters 1 ghost 1 hat 3 watches