Can you identify the hidden rebus in the image below?

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?

One is to three as three is to five and five is to four and four is the magic number.
What is the pattern?

You can hear me, but you can't touch or see me.

What am I?

Make eight squares by moving only two matchsticks.
Note- Square can be of different sizes.

What does it mean?

Can you complete the sequence puzzle?

AR TA GE CA LE VI LI _

A Doctor always sneezes before the rain. Doctor sneezes, Will it rain?

I came first on earth but second on the heaven.
I also came twice in a week but found just once in a year.
I stay away from months but you can find me in February.

What am I?

In a jungle where there are no street lights or any other artificial source of lights, I notice a black snake crossing the road.
How did I get sight of the snake?