What brings you down but never up?

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?

Count the number of triangles in the below picture?

John killed hundreds of people mercilessly and yet the police were not able to put her behind the bars. Why?

Divide 110 into two parts so that one will be 150 per cent of the other. What are the 2 numbers?

There was a man he lives in a hotel each morning he presses the first floor button each evening if there is a person in the elevator he asks him to press the 10 floor button if there is no one in the elevator he takes the stairs why.

What is common among 11, 69, and 88?

Rahul decided to meet Simran so he boards a local train from Bombay station. Just after the station, there is a 1km long tunnel. The train starts and is now accelerating. Rahul is a claustrophobic guy, so what is the best position for him to sit?

They do not possess flesh or feathers or scales or bone
But still, they are blessed with fingers and thumbs of their own.

The barber of Town shaves all men living in the town. No man living in the town is allowed to shave himself. The barber lives in that town. Who then shaves the barber of the town?