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

Can you find the key in the picture below?

Baseball bat and ball cost $100. If the bat cost $99 more than the ball, what is the cost of each?

See the given image carefully. What you have to do is move the blue checkers in the position of the black checkers and vice versa. You are only allowed to move the checker to an adjacent empty space. Do it in the least possible moves.

A man is lying dead in a field where no one is around. His head is split open and his legs are disfigured. Near to him, there is an unopened package. No living organism can be found anywhere at the crime scene.

How did he die?

As a whole I am both
safe and secure.

Behead me and I become
a place of meeting.

Behead me again and I am
the partner of ready.

Restore me, and I become
the domain of beasts.

What am I?

In the given figure, you can see that four match sticks are used to form a square. Can you form five squares by using six matches?

Vin Diesel is pulling a theft and has planned to run away with all the cash kept in the safe. But the only way to open the safe is the 13 character password. He has a set of five clues given to him by a trustworthy source.

Exactly two of the below statements are false.
The password is contained within this sentence.
The password is not in this hint.
The password is within only one of these statements.
At least one of the above statements is a lie.

What is the riddle which can be asked all day with a different correct answer each time.

Complete the following series. It.s very logical:

1, 4, 5, 6, 7, 9, 11, __?