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?

You can see it everyday, But cannot touch it at will. What is it?

Mr Black, Mr Gray, and Mr White are fighting in a truel. They each get a gun and take turns shooting at each other until only one person is left. Mr Black, who hits his shot 1/3 of the time, gets to shoot first. Mr Gray, who hits his shot 2/3 of the time, gets to shoot next, assuming he is still alive. Mr White, who hits his shot all the time, shoots next, assuming he is also alive. The cycle repeats. If you are Mr Black, where should you shoot first for the highest chance of survival?

A father's child, a mother's child, yet no one's son.

Who am I?

A man was driving a black truck. His lights were not on. The moon was not out. A lady was crossing the street. How did the man see her?

How many points are there on the globe where, by walking one mile south, then one mile east and then one mile north, you would reach the place where you started?

If your uncle’s sister is not your aunt, what relation is she to you?

Replace the question mark with the correct number, given the pair of numbers exhibits a similar relationship?

? : 3839 :: 11 : 1209

I’m tall when I’m young, and I’m short when I’m old. What am I?

You can take four of the five letters out of this word, but the pronunciation never changes. What is the word?