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

Prove that the below maths equation is true.

8 + 8 = 91

Keyboard words are not in alphabetical order, Why?

I am Huge on Sunday and Saturday.
I am small from Tuesday to Thursday.
I do not exist on Monday and Friday.
Who am I?

I am sure no one can have two things for dinner. what are they?

The product of three consecutive numbers is 7980.
Then the sum of these consecutive numbers would be?

I hide my treasure in the ground, my tail is big and fluffy. If you spot me in a tree, please don’t call me scruffy. What am I?

A man was gazing through the window of the 23rd floor of the building. He suddenly opened the window and jumped on the other side of the window. On landing on the floor, there was not a sheer mark of injury on him.

How can that be possible if he did not use any kind of parachute and did not land on a soft surface?

How many pluses should we put between the digits of 987654321 to get a total of 99, and where?

On her drawing table, Sayna lit 12 coloured candles. A few seconds later she blew two candles off.

How many candles Sayna have at the end?