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

What has one letter and starts with an E?

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

Open a Laptop which is password protected. Hint for the password is given as below:

1 mobile 3 books 2 Boards 1 night 4 balls 2 lighters 1 ghost 1 hat 3 watches

Why is 6 afraid of 7?

How can you tell a raw egg from a hard-boiled egg?

Two guards were on duty outside a barracks. One faced up the road to watch for anyone approaching from the North. The other looked down the road to see if anyone approached from the South. Suddenly one of them said to the other, "Why are you smiling?"

How did he know his companion was smiling?

What question can you never answer yes to?

There was an aeroplane crash, every single person died, but two people survived. How is this possible?

Can you find out the next digit in the following series ?

0, 0, 1, 3, 2, 6, 3, 9, 4, 12, 5, ?