What does below Rebus mean ?

esgg sgeg gegs gsge

In the addition below, all digits have been replaced by letters. Equal letters represent equal digits and different letters represent different digits.
ABCABA
BBDCAA
ABEABB
ABDBAA
------- +
AAFGBDH
What does the complete addition look like in digits?

Before Mount Everest was discovered, what was the highest mountain in the world?

I am an eight letter word and I am a computer terminology.
The second, third and fourth letters make an animal.
The fourth, fifth, sixth, seventh and eighth letters make a weapon.
The first, second, third and fourth letters can be taken as an outcome of any exam.
The fifth, sixth, seventh and eighth letter combine to form a high end typing software.

Can you tell who am I ?

If you had a pizza with crust thickness 'a' and radius 'z', what's the volume of the pizza?

A B C D E F G H

These are the letters given to you. Now you have to find out the letter that comes two to the right of the letter which is immediately to the left of the letter that comes three to the right of the letter that comes midway between the letter two to the left of the letter C and the letter immediately to the right of the letter F.

The below mentioned letters have been placed in a order using a logic.

DEAD, BALL, FEAR, SHOP

Can you find the logic?

Can you solve the below tricky visual equation?

What mathematical symbol can be put between 5 and 9, to get a number bigger than 5 and smaller than 9?

I am the one who remains awake when you sleep. But I need to rest when you awake. Who Am I?