The more of this there is, the less you see. What is it?

Look at this sequence from top to bottom. What is the next number in the sequence?
1
11
21
1211
111221
312211

Can you find out which options fits best with the missing column?

A shepherd had 18 sheep, out of which, all but ten died.

Can you tell us how many sheep was he left with?

I am a normal creature, but I have five hands. I can even have more but even then I will be considered normal.

Who am I?

Find three whole, positive numbers that have the same answer when multiplied together as when added together.

A man was found murdered on Sunday morning. His wife immediately called the police. The police questioned the wife and staff and got these alibis: The Wife said she was sleeping. The Cook was cooking breakfast. The Gardener was picking vegetables. The Maid was getting the mail. The Butler was cleaning the closet. The police instantly arrested the murderer. Who did it and how did they know?

A girl was sitting in her hotel room when she heard a knock on the door. She opened the door and found that a man was standing outside.
The man said, "Oh! I am really sorry, I thought this was my room."
He then walked through the corridor to the elevator. The girl did not know the man. She closed her door and called security asking them to apprehend the man.
What made her suspicious of that man? He might have been genuinely mistaken.

What is next number in the pattern below:

131 517 192 123 ?

How can you make number one disappear by adding something to it?