What has no start, end, or centre?

If eleven plus two equals one, what does nine plus five equal?

What is the centre of gravity?

There is a box in which distinct numbered balls have been kept. You have to pick two balls randomly from the lot.

If someone is offering you a 2 to 1 odds that the numbers will be relatively prime, for example
If the balls you picked had the numbers 6 and 13, you lose $1.
If the balls you picked had the numbers 5 and 25, you win $2.

Will you accept that bet?

I am quite hot but become too cold if you remove the first two letters. What am I?

Can you decipher the below rebus?

PBLUESAISNUERSES

Why are all black people so quick ?

Find out which of the given views in the picture is accurately the top view of the given pyramid.

A few friends are enjoying their sea voyage in a boat full of apples. On the way, they felt hungry and thus decided to eat the apples. Together, they ate two dozen of apples. When they have eaten the apples, will there be any change in the water level?

Samuel was out for a walk when it started to rain. He did not have an umbrella and he wasn't wearing a hat. His clothes were soaked, yet not a single hair on his head got wet. How could this happen?