Identify the hidden meaning behind this picture?

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?

You are given with the following sum. Each of the letters can be decoded as a digit. If we tell you that D = 5, then can you solve it entirely?

DONALD
+GERALD
=ROBERT

An equation has been laid down using a few matchsticks. However, as you can see, the equation is not correct. Can you correct the equation if you are allowed to add or remove 5 matchsticks?

Can you quickly find which two matchstick figures are identical?

Can you spot the hidden girl in the picture below?

What will you call your mother's brother's brother-in-law?

What number comes next in this sequence:
7 8 5 5 3 4 4 _

In the image below, you can see two glasses and two matchsticks.You need to move four matchsticks in such a manner that the crosses come inside the glasses. Note: you cannot move the crossed.

When you say goodbye, I am what you need to tie.
I come as a couple and go wherever you run.
Who am I?