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?

What is next number in the pattern below:

131 517 192 123 ?

Always in you, Sometimes on you;

If I surround you, I can kill you.

What am I?

How is the moon similar to a dollar?

Find the next number in the series.
1 10 24 43 67 ?

What has lots of eyes, but can’t see?

what's the probability of getting a king or a queen from a pack of 52 cards?

I know a ten-letter word in the English language which can be typed using only the top rows of the computer keyboard.

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

In a box, there is a jumble of 7 red balls, 6 blue balls, 5 green balls, and 4 yellow balls. What is the minimum number of balls, will you have to pick up so that you have at least 4 balls of the same colour?