An infinite number of mathematicians are standing behind a bar. The first asks the barman for half a pint of beer, the second for a quarter pint, the third an eighth, and so on. How many pints of beer will the barman need to fulfill all mathematicians' wishes?

I am a three digit number.
My tens digit is five more than my ones digit.
My hundreds digit is eight less than my tens digit.
What number am I?

A mother is 21 years older than her child. In exactly 6 years from now, the mother will be exactly 5 times as old as the child.
Where's the father?

In particular commonwealth games, a female participant won silver and gold medals for a single event.

How can this be possible?

This is a picture puzzle. You have to guess the name of the movie that can be related to the picture.

Can you find the thief by just looking at the picture below?

I’m light as a feather, yet the strongest person can’t hold me for five minutes. What am I?

What goes up but never comes down?

How much will a 38° angle measure when looked at under a microscope that magnifies ten times?

When Jack was six years old he hammered a nail into his favourite tree to mark his height. Ten years later at age sixteen, Jack returned to see how much higher the nail was. If the tree grew by five centimetres each year, how much higher would the nail be?