Can you find out which number multiplied by itself will give the output as 12345678987654321?

What jumps when it walks and sits when it stands?

What occurs twice in a week, once in a year but never in a day?

A man stands on one side of a river, his dog on the other. The man calls his dog, who immediately crosses the river without getting wet and without using a bridge or a boat. How did the dog do it?

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

The answer I give is yes, but what I mean is no. What was the question?

Three doctors said that Bill was their brother. Bill says he has no brothers. How many brothers does Bill actually have?

I am an eight letter word and I am a computer terminology.
The second, third and fourth letters make an animal.
The fourth, fifth, sixth, seventh and eighth letters make a weapon.
The first, second, third and fourth letters can be taken as an outcome of any exam.
The fifth, sixth, seventh and eighth letter combine to form a high end typing software.

Can you tell who am I ?

What has one eye, but can’t see?

A prisoner is told: "If you tell a lie, we will hang you and if you tell the truth, we will shoot you." What did the prisoner say to save himself?