What does this rebus mean?

O
N
C
E
TIME

Why 1729 is a magic number? Answer Logically.

You have an empty wine bottle with a cork that has been secured at the top in a normal way. There is a metal ring inside the bottle that is suspended by a string.

How can you make the metal ring drop to the bottom if you are not allowed to touch anything - not the bottle, not the cork, not the thread and not the ring?

An evil man kidnapped someone and made them take one of two pills. One was harmless, but the other was poisonous. Whichever pill the victim took, the kidnapper took the other one. The victim took their pill with water and died. The kidnapper survived. How did the kidnapper get the harmless pill?

The measurement of time, That can't be found on a clock, But can be looked upon on a map.

Who is He ?

There are are five things wrong with this sentence; only geniuses will be able to to spot all of the mitstakes

I left my campsite and hiked south for 3 miles. Then I turned east and hiked for 3 miles. I then turned north and hiked for 3 miles, at which time I came upon a bear inside my tent eating my food! What colour was the bear?

I am written with two letters.
I said with the one.
I usually am seen with the two.

Who am I?

A 52% bias toss for head using the 51% tail bias coin was done to obtain a fair result.

Can you find how bias is the floor in this case?

Why are all black people so quick ?