Complete the following series. It.s very logical:

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

In the Chess Board picture below white army is arranged. You need to add a black army on the board such that no piece is under any threat.
Note: Army comprised of 1 king, 1 queen, 2 rooks, 2 bishops, 2 knights, and 8 pawns.

The centre of the third figure is empty. What digit should fit inside?

Why Aeroplane windows are round?

To tease, King Akbar told his most clever advisor Birbal to give his daughter one thing that she can eat when hungry, drink if she feels thirsty and can burn if she feels cold. King Akbar was shocked when Birbal gave Akbar's daughter one such thing that satisfies all of the above.

What did Birbal give to Akbar's daughter?

I have cities, but no houses. I have mountains, but no trees. I have water, but no fish. What am I?

What does this rebus mean?

O
N
C
E
TIME

What jumps when it walks and sits when it stands?

Replace each alphabet with the number (1-9) to make the below equation correct.

AB * C = DE - F = GH / I

It comprises roots which nobody sees,
Much taller than those trees,
Up and up it goes,
Still it never grows?