How can a man go eight days without sleep?

They are three errirs in this question. Can you find them?

There are nine letters in the below-given diagram. You have to form a nine-letter word using these letters.

You find yourself in a strange place guarded by two guards.One of the guard always say truth while other always lies.You don't know the identity of the two.You can ask only one question to go out from there. What should you ask?

A chicken farmer has figured out that a hen and a half can lay an egg and a half in a day and a half. How many hens does the farmer need to produce one dozen eggs in six days?

Two boys were admitted to a school. When the headmaster asks them about their parents, they tell him that they have same parents (father and mother). On further inquiry, it turns out that they both share the same date for their birthday.

"Are you twins," ask the headmaster.
"No," replies the boys.

Is it possible?

Make a sentence consisting of three words that have the whole alphabet.

It comprises roots which nobody sees,
Much taller than those trees,
Up and up it goes,
Still it never grows?

If you remove one from eleven, it becomes ten. If you remove one from nine, it becomes ten.

How is this possible?

What's the only room from which no one can enter or leave