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

Out of four images which one is the odd one out?

A river should be crossed by a father, a mother and their two sons and two daughters.
There are some rules that should be followed while crossing the river. There can be only two people in the raft while crossing. The daughters cannot be with their father unless there is the presence of the mother. The sons cannot be with their mothers unless the father is present. Unless the guard is on the board, the criminals cannot be with any of the family members. Only the adults like the father, the guard, and the mother knows to use the raft.

How will they cross the river?

By moving just one matchstick, you need to make the below statement true. Can you do it?

What do you think with the below Picture ?

Solve the below puzzle by replacing the question mark with the correct number.

3 6 12

4 8 16

5 10 ?

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

Rebus Puzzle Definition: A rebus is an illusion device that uses pictures to represent words or parts of words.
What does This Rebus Puzzle Identify?

They are the five precious gems of an everyday sort and all can be found on a Tennis Court. Who are they?

What's the next in the series?

H, Be, F, S, Mn, Kr, In, Gd, Tl, ?