What is the Surname of Barbie Doll?

In the picture, you can see a chess board. On the top left position, the K marks a knight. Now, can you move the knight in a manner that after 63 moves, the knight has been placed at all the squares exactly once excluding the starting square?

An infinite number of mathematicians are standing behind a bar. The first asks the barman for half a pint of beer, the second for a quarter pint, the third an eighth, and so on. How many pints of beer will the barman need to fulfill all mathematicians' wishes?

Replace the question mark with the correct number.

Can you find the odd number in the following?

2716, 4135, 5321 and 7145

It's a protector.
It sits on a bridge.
One individual can see directly through it, while others wonder what it hides.

What is it?

What has six faces, but does not wear makeup, has twenty-one eyes, but cannot see?

Solve the equation by replacing the alphabet with numbers.

MOM + MOM + NO = BOOK=

I am a type of room you cannot enter or leave. Raised from the ground below, I could be poisonous or a delicious treat. What am I?

Find the hidden tiger in the given optical illusion ?