What is the fastest way to double your money?

A detective visits his friend John just to discover that John's neighbour Dr Jacob was murdered. Dr Jacob, who is a mathematician wrote the murderer's name in a code word "Hcqtfz". There were five suspects
1. Ajit
2. Pankaj
3. Ganpat
4. Deenu
5. Hariya

The Detective was instantly able to find the murderer.
Can you?

What is common among 11, 69, and 88?

There was a strange boy who was born before his father. How can this be possible?

Who always enjoys poor health?

You need to pick one entry from pot A and one from pot B to have a perfect match. Can you do it?

Can you identify the direction in which this bus is moving; left or right?

Hint: The bus is moving on the roads of London.

What always comes into a house through the keyhole?

A boy purchased a book from a bookkeeper and gave him $100.
The cost of the book is $50 but the bookkeeper has no change, so he gets the change from the next shop and returns the boy his $50.

After some time the next shopkeeper came with the $100 note and told the bookkeeper that the note was a fraud, so he took the money back.

How much loss did the bookkeeper face?

What is red and smells like blue paint?