Which number should replace the question mark?

Bay of Bengal is in which state?

You have two buckets of 11 liters and 6 litres.
How can you measure exactly 8 litres?

What goes up but never comes down?

I have Rs.50 and I spend it in the way as below.

John left on a horse on Thursday , was gone for two days, and came back on Thursday after completing his work. How did that happen?

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?

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?

In a secret society, a buried chamber can be accessed only via a secret password. The password is seven characters long and comprises of just letters and numbers.

You find a code that can help you in cracking the password. The code says "You force heaven to be empty".

Can you deduce the password from that?

Luis Garavito killed Density x Volume.

Who is Luis Garavito ?