What does this mathematical rebus means ?

What is the last thing you take off before bed?

Take away my first letter, then take away my second letter. Then take away the rest of my letters, yet I remain the same. What am I?

What has no start, end, or centre?

There was once a college that offered a class on probability applied to the real world. The class was relatively easy, but there was a catch. There were no homework assignments or tests, but there was a final exam that would have only one question on it. When everyone received the test paper it was a blank sheet of paper with a solitary question on it: 'What is the risk?'.Most students were able to pass, but only one student received 100% for the class! Even stranger was that he only wrote down one word!
What did he write?

I travel all around the world but always stay in the corner. What am I?

A bank customer had $100 in his account. He then made 6 withdrawals. He kept a record of these withdrawals, and the balance remaining in the account, as follows:

Withdrawals Balance left
$50 $50
$25 $25
$10 $15
$8 $7
$5 $2
$2 $0
----- -----
$100 $99

Why are the Totals not tallying?

There was a competition where the contestants had to hold something. At the end of the event, the winner was a person who had no hands or feet. What was it that the contestants had to hold?

Can you find out the number that should replace the question mark with a valid reason?

Which three-digit number, made of consecutive digits, like 567, is 2 less than a cube and 2 more than a square?