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

What is the Surname of Barbie Doll?

81 x 9 = 801. What must you do to make the this equation true?

Find three numbers such that

* When we multiply three numbers, we will get the prime numbers.
* The difference between the second and the first number is equal to the third and second.

What has 88 keys?

Can you find out which options fits best with the missing column?

I was born in a small house and I live in it all alone. No windows and no doors have been assigned to my house. The only way I can go out is by breaking through the walls of my house.

Who am I?

There is something which you can be arrested for attempting but not for successfully completing.

A shepherd had 18 sheep, out of which, all but ten died.

Can you tell us how many sheep was he left with?

When my father was 31 I was 8. Now he is twice as old as me. How old am I?