Spot 5 differences in two Christmas tree below:

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?

It's a test that will check your IQ.

Suppose you have one 11 minute hourglass and one 13 minute hourglass.

Can you measure exactly fifteen minutes using them ?

It is always ahead of me yet I can never see it. What is it?

When it's bad luck to meet a black cat?

Count the squares in the matchstick puzzle below?

I know a 5-digit number having a property that With a 1 after it, it is three times as large as it would be with a one before it.

Guess the number?

If you remove one from eleven, it becomes ten. If you remove one from nine, it becomes ten.

How is this possible?

Samuel was out for a walk when it started to rain. He did not have an umbrella and he wasn't wearing a hat. His clothes were soaked, yet not a single hair on his head got wet. How could this happen?

What number divided by 4 is the same as that number minus 4?