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?

Imagine a box with two cogwheels, one big with 24 teeth and one small with 8 teeth. The big one is firmly attached to the center of the box which means it does not turn or move while the small one rotates around the big one.

How many times do you think that the smaller wheel will turn compared to the box when it turns once around the big one?

Complete the table series riddle by finding the number that can replace "??".

You are given four results as below:
1111 = F
2222 = E
3333 = T
Then, can you find out how to code 4444?

If a shopkeeper can only place the weights on one side of the common balance. For example, if he has weights 1 and 3 then he can measure 1, 3 and 4 only. Now the question is how many minimum weights and names of the weights you will need to measure all weights from 1 to 1000? This is a fairly simple problem and very easy to prove also.

My cousin lives in one story house in Antarctica. His house is made the of-of sandstone. what is the color of stairs?

Can you place three balls such that the equation shown in the picture holds true?

Use only one mathematical symbol and all numbers (0-9) to get a sum of 99

On a magical land of Mexico , all the animal in the land are rational.

There are 10 tigers and one goat.
Tiger can eat goat but since it's a magical land , the tiger who eats the goat , turns into goat and then can be eaten by the remaining tiger(s).

If we leave them for some time then how many goat and tiger will be there , when we come back ?

You walk into a room that contains a match, a kerosene lamp, a candle and a fireplace. What would you light first?