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

He runs but never walks. Murmurs, but never talks. Has a bed, but never sleeps. And has a mouth, but never eats?

What does below pictogram mean?

Make eight squares by moving only two matchsticks.
Note- Square can be of different sizes.

John left on a horse on Thursday , was gone for two days, and came back on Thursday after completing his work. How did that happen?

What is always in front of you but can’t be seen?

There were two grandmothers and their two granddaughters.
There were two husbands and their two wives.
There were two fathers and their two daughters.
There were two mothers and their two sons.
There were two maidens and their two mothers.
There were two sisters and their two brothers.
Yet there are only six, who are buried here,
All are born legitimate and relationships clear.
How can this happen?

In which direction should the missing arrow point?

You are provided with a grid (as shown in the picture). Can you fill the squares with numbers 1-8 in a manner that none of the two consecutive numbers are placed next to each other in any direction (vertically, horizontally or diagonally?)

What does this rebus riddle means ?