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

Which of the below owl is odd one out?

ENEMY = 2 * LINK
LINK + 2 = HELL

Then what will be TAXI + HELL? Select from the options below:
a) ROTTEN
b) DANGER
c) HEAVEN
4) MORTAL

A non-stop marathon is the shared favourite sport of three brothers.

*The oldest one is fat and short and trudges slowly on.
*The middle brother's tall and slim and keeps a steady pace.
*The youngest runs just like the wind, speeding through the race.

"He is young in years, we let him run!" the other two brothers explained, "'because though he is surely number one, he is second, in a way." Why is it?

Can you name an animal whose killing cannot be performed without spilling your own blood?

What is the last thing you take off before bed?

As easy as you can get into me, it is as hard to get out of me.

Do you know what I am?

I add 5 to 9 and get 2. The answer is correct, so what am I?

You have an empty wine bottle with a cork that has been secured at the top in a normal way. There is a metal ring inside the bottle that is suspended by a string.

How can you make the metal ring drop to the bottom if you are not allowed to touch anything - not the bottle, not the cork, not the thread and not the ring?

What number comes next in this sequence:
7 8 5 5 3 4 4 _