Solve the riddle below:

If a Chicken says, 'All chickens are liars" is the chicken telling the truth?

10+10 and 11+11 can give you the same answer.

Explain how?

Forwards I am heavy, backward I am not. What am I?

What is the difference between a jeweller and a jailer?

Who always enjoys poor health?

I am a type of word that is spelt incorrectly or used differently, on purpose for humour. What am I?
Hint 1: You can find me in a joke.
Hint 2: I am a play on words.

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?

Teacher ask the student

'Why are you standing on that chair in music class ?'.

what did student replied ?

What does the below mathematical rebus mean?

I am five letter word that is under you.
If you remove my 1st letter, then I am over you.
If you remove my 1st and 2nd letters then I am all around you.

Who am I?