What does below rebus means ?

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 need to arrange three 7 and mathematical symbols to form number 1?

What question can you never answer yes to?

What does an Island and the letter T have in common?

I am white when I am dirty, and black when I am clean. What am I?

Can you find the missing letter in the sequence?
S - T - I - L - ? - T - F - Y - C

Why is a river so rich ?

Which tank will fill first?

Replace the 'X' with any mathematical symbol to make the expression equal to 111.

18 X 12 X 2 X 3 = 111