Which number should replace the question mark?

Edward James went for tiger hunting.

It was not his lucky day.



He got six tigers without heads, nine tigers without the tail and eight cut in two halves.

How many tiger did he hunted ?

What goes up but never comes down?

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?

While going to your grandmother's house, you counted Twenty houses on the right side. While returning back to your home, you counted Twenty houses on the left side.

How many houses are there between your home and your grandmother's home?

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

I come in different shapes and sizes.
Parts of me are curved, other parts are straight.
You can put me anywhere you like,
but there is only one right place for me.
What am I?

Luis Garavito killed Density x Volume.

Who is Luis Garavito ?

There are two candles. Both will only burn exactly for an hour. How will you use these two candles to measure forty-five minutes?

John and his team plan to rob a safe. They got just one chance to break the code else the local police will be informed. Below are clues:
A) Exactly one number is perfectly placed: 9 8 1
B) Everything is incorrect: 9 2 4
C) Two numbers are part of the code of the safe but are wrongly placed: 0 9 3
D) One number is part of the code of the safe but is wrongly placed: 1 4 7
E) One number is part of the code of the safe but is wrongly placed: 7 8 3