What building has the most stories?

In a boat, the father of a sailor's son is sitting with the son of the sailor. However, the sailor is not present on the boat.

Can this even be possible?

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.

Can you count the number of triangles in the given figure?

When you stop to look, you can always see me. But if you try to touch me, you can never feel me. Although you walk towards me, I remain the same distance from you. What am I?

Railroad Crossing, look out for the cars. Can you spell that, without any R's ?

You have three orange, two pink and five purple balls in the drawer beside your bed. There is no electricity and the room is entirely dark. How many balls must you take out to ensure at least one ball of each colour at least?

I am the beginning of the end, and the end of time and space. I am essential to creation, and I surround every place. What am I?

They came out at night, without being called.
They lost at day, without being stolen.
Who are they?

What's a single-digit number with no value?