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

We have four gears with below features=> Both Gear A and D has 60 teeth=> Gear B has 40 teeth=> Gear C has 20 teeth=> Every two minutes, Gear B makes 25 full turns.What is the relative speed of Gear A and Gear B?

How can you take 2 from 5 and leave 4?

All of you like to eat me. I am a five-lettered word. Remove the first two and I turn into an infamous animal. Remove just the first and I become a heinous crime. Remove the first and the last and you can groove on me.

Can you guess who am I?

How many words can a quill made with the feather of a pigeon write with a 100ml bottle of black ink?

Spelt forwards I’m what you do every day, spelled backwards I’m something you hate. What am I?

John is selling fruits.
He sells grapes at $30, Dates $25, and a Wolfberry $45.
At what price does he sell fig?

PS: Logical Thinking

There are nine letters in the below-given diagram. You have to form a nine-letter word using these letters.

What is the word or phrase?

Different lights make me strange by changing me into different sizes. What am I?