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?

If 1+9+8=1, what is 2+8+9?

My thunder comes before the lightning; my lightning comes before clouds; my rain dries all the land it touches. What am I?

Astrology starts with the alphabet A, Biology starts with B, Psychology with P and Limnology with L.

Can you find an "ology" that begins with a P?

A man stands on one side of a river, his dog on the other. The man calls his dog, who immediately crosses the river without getting wet and without using a bridge or a boat. How did the dog do it?

A mad serial killer kidnaps people and forces them to play the game of 2 pills with them, In this game, there are pills in the table and one of them is normal pill while the other one is deadly poisonous.
The victim will choose one pill and the killer will pick the other pill and both simultaneously will swallow the pill with water.
victim dies every time.

One day the serial killer kidnaps the Joseph and forces him to play the same game with him.

Joseph solves the mystery of the two pills and remains alive.

Explain?

Jenifer is learning to drive her car. She went down a one way lane and in the wrong direction. But she do not break any law.

How come ?

What is the word or phrase?

Decode below three cipher riddles:

26 L of the A
7 D of the W
1000 Y in a M

I possess a head

I flaunt a tail

But I don't have mouth or legs

Can you find out who I am?