Complete the following series. It.s very logical:

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

What has many keys but can’t open a single lock?

Replace the question mark with the number below given a simple math problem.

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

Can you think of a smallest +ve number such that if we shuffle the digits of the number, the new number becomes double the original number?

A number can be multiplied by multiple of nine
i.e 9 18 27 36 45 ...

and the resulting number consist of only one digit.

Can you identify the number ?

There is a family that live in a round house. The two parents go out for a movie and leave a babysitter to watch their son. They come back and the kid was not there. Some one kidnapped him. The maid said she was cleaning in a corner. The cook said he was making pizza. The babysitter said she was getting a board game. Who kidnapped him.

Can you make the below equation true by using any three numbers from "1, 3, 5, 7, 9, 11, 13 and 15"?

( ) + ( ) + ( ) = 30

How can you drop a raw egg from a height onto a concrete floor without cracking it?

Complete the table series riddle by finding the number that can replace "??".