Why are televisions attracted to people?

A chess tournament is taking place on knock-out terms (the one who loses the match is out of the game).
(a) If 10 matches are played in total, how many players participated?
(b) If 20 players took part in the tournament, how many matches were played?

Identify the 10 differences between the two given pictures.

My friends called me Iron59 because my parents are a chemist and a mathematician. What is my real name?

What goes up but never comes down?

You see a boat filled with people, yet there isn’t a single person on board. How is that possible?

How can you tell a raw egg from a hard-boiled egg?

What has a bottom at the top?

What occurs twice in a week, once in a year but never in a day?

Place a mathematical symbol between the numerals 5 and 9 in such a way that the resulting number is greater than 5 but smaller than 9.