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

Can you spot the man between the coffee bean in the picture below ?

One night, a woman receives a call from the police. They tell her that her husband was murdered and that she should come to the crime scene as soon as possible. The woman drops the phone, shocked, and drives 20 minutes to the crime scene. As soon as she reaches the crime scene, the police arrest her and she is convicted of murder. How do the police know she committed the crime?

Can you name any English verb that becomes its past tense by simply rearranging the alphabets ?

John has played 50 ODI's and his average is 50. How many runs should he score in his 51st ODI, so that his average score jumps to 51?

What type of tree can I carry in my hand?

I have a mouth but I don't eat.
I have a bank but have no money.
I have a bed but i dont sleep.
I wave but have no hands.

Who Am I ?

It belongs to you, but other people use it more than you do. What is it?

A couple went on a climbing trip. But only the husband returned from the vacation and said that his wife slipped off while climbing and died. On investigating, the local sheriff arrested him saying, 'Your travel agent called. You murdered your wife.'

The man did not inform anyone about the trip. Then how was the agent so sure that it was a murder?

Lifeless eyes on my smiling face and watch your child's sleeping place. In their dreams they hold me tight. What am I?