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

A maths symbol is hidden in the below Bar Graph. Can you decipher it?

Can you solve this amazing hard number series problem?
7, 8, 10, 12, 16, 18 ?

Can you solve the below algebraic mathematical equation?

(J+O+I+N+T)3 = JOINT

Irene killed hundreds of people mercilessly and yet the police were not able to put her behind the bars. Why?

I am thinking of a five-digit number such that:
The first and last digits are the same, their submission is an even number and multiplication is an odd number and is equal to the fourth number. Subtract five from it and we obtain the second number. Then divide into exact halves and we get the 3rd number.

What number I am thinking of?

There is one thing that goes round the house and also inside the house but never even share a brief touch. What is it?

Find out the missing number in the picture attached:

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?

A bomb goes off.
Carnage.
One person, only a few feet away, survives! How can this be?