What is the word or phrase?

For an extra income, John decided to work at a Hotel for one hour daily. The manager offers him that they will pay him $11 after every 11 days.
However, John offered a different proposition to the manager. The offers stand as:
He will be paid just a penny on his first day.
Two pence will be paid on the second day,
Four pence will be paid on the third day.
And so on till the 11th day.

Should the Hotel manager accept his offer?

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 ?

Which alphabet letter is a question?

Can you calculate the probability of getting a sum of six when a dice is thrown twice?

Decode below rebus
D
N
A
T
S , D

What is so fragile that saying its name breaks it?

There are forty elephants and they have forty-fore heads. How can this be possible?

Mother's Name is Mrs. SIXTY TWO
Son's Name is FIFTY TWO
Daughter's Name is FORTY TWO
What is Name of Father?