A maths symbol is hidden in the below Bar Graph. Can you decipher it?

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 it be possible to build a house that has all its four walls facing towards the South?

A bomb goes off.
Carnage.
One person, only a few feet away, survives! How can this be?

Can you find out which number multiplied by itself will give the output as 12345678987654321?

A boy was locked in a room by some robbers. All that is in the room is a piano, a calendar, and a bed. The room is locked from the outside. What does he eat, drink, and how does he escape and get out?

Can you arrange four 9's and use at most 2 math symbols, to make the total 100?

Replace the question mark with the correct number in below Picture:

In which direction should the missing arrow point?

A man walked into a pub and went straight towards the Barman. He asked for a dirty martini from the Barman. The Barman thought something and then pulled out a pistol from his drawer and aimed it directly at the man. Why did he do that?