What is the fastest way to double your money?

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

How can this be possible?

Intelligence Agency need to break the vault but the problem is that they are not able to break the vault.

On the vault, a text is written as:

31 11 33 33 43 45
21 25
31 24 11 31 51 41

To Break the code Intelligence Agency brings a mathematician named Joseph.
Minutes later he deciphers the code.

Whats the code?

I have a hole in my back and legs I lack.
I live where I can’t breathe and I eat without teeth.
What am I?

what does the below rebus means?

A man is trapped in a room. The room has only two possible exits doors. Through the first door there is a room constructed from magnifying glass. The blazing hot sun instantly fries anything or anyone that enters. Through the second door there is a fire-breathing dragon. How does the man escape?

It belongs to you, but other people use it more than you do. What is it?

Can it be possible to build a house that has all its four walls facing towards the South?

What has six faces, but does not wear makeup, has twenty-one eyes, but cannot see? What is it?

It is an eleven letter word.
The first, second, third and fourth letters form a banquet's name.
The fifth, sixth and seventh letters form a car's name.
The eighth, ninth, tenth and eleventh letters form a mode of transport.

Can you identify what word it is?