Can you find out the total number of triangles in the given figure?

A man lives on the fifteenth floor of an apartment building. Every morning he takes the elevator down to the lobby and leaves the building. In the evening, he gets into the elevator, and, if there is someone else in the elevator, or if it was raining that day, he goes back to his floor directly. Otherwise, he goes to the tenth floor and walks up five flights of stairs to his apartment. Can you explain why he does this?

Can you solve below mathematical equation?

2^1234 - 2^1233

I speak without a mouth, and hear without ears. I have no-body, but I come alive with the wind. What am I?

Spelt forwards I’m what you do every day, spelled backwards I’m something you hate. What am I?

You are given four tennis balls and asked to arrange those balls in a manner that the distance between each one of them is exactly equal. How will you do it?

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.

I can be cracked, made, told, and played. What am I?

The picture shows the dice results in each couple of throws. If they are actually following a pattern, can you find out the missing one?

Complete the following series. It.s very logical:

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