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

Explain how?

What does this simple rebus mean?

Three fair coins are tossed in the air and they land with heads up. Can you calculate the chances that when they are tossed again, two coins will again land with heads up?

who is silent in the parliament?

What is next number in the pattern below:

131 517 192 123 ?

Three ants are going up a hill, one behind the other. The last ant then says to the other ants, 'There is an ant behind me!'' How come?

There are people and strange monkeys on this island, and you can not tell who is who (Edit: until you understand what they said - see below). They speak either only the truth or only lies.
Who are the following two guys?
A: B is a lying monkey. I am human.
B: A is telling the truth.

Why did the Girl throw the butter out of the window?

What has a bottom at the top?

If you remove one from eleven, it becomes ten. If you remove one from nine, it becomes ten.

How is this possible?