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

Can you name some countries which do not have the alphabet 'A' in them?

In a chess board, the queen piece can move horizontally, vertically and diagonally freely. The picture represents the same.Can you place 8 queens on the board in a manner that none of the queens can attack each other?

Can you name three consecutive days without using the words Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, or Sunday?

What does below Rebus mean ?

esgg sgeg gegs gsge

An equation has been laid down using a few matchsticks. However, as you can see, the equation is not correct. Can you correct the equation if you are allowed to add or remove 5 matchsticks?

It has a long neck, A name of a bird, Feeds on cargo of ships, It's not alive,

What is it?

There is something which is always coming but never arrives?

If "P" means "-", "Q" means "/", "R" means "+", and "S" means "*" then find the value of the following:

21 Q 7 R 9 S 10 P 13

I am a prime number.
The double of myself is equal to the square of me.

which number am I?