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

What can run but never walks, has a mouth but never talks, has a head but never weeps, has a bed but never sleeps?

what does this picture(rebus) riddle means ?

I can sizzle like bacon,
I am made with an egg,
I have plenty of backbone, but lack a good leg,
I peel layers like onions, but still remain whole,
I can be long, like a flagpole, yet fit in a hole.

My thunder comes before the lightning; my lightning comes before clouds; my rain dries all the land it touches. What am I?

Railroad Crossing, look out for the cars. Can you spell that, without any R's ?

Samuel was out for a walk when it started to rain. He did not have an umbrella and he wasn't wearing a hat. His clothes were soaked, yet not a single hair on his head got wet. How could this happen?

Imagine a box with two cogwheels, one big with 24 teeth and one small with 8 teeth. The big one is firmly attached to the center of the box which means it does not turn or move while the small one rotates around the big one.

How many times do you think that the smaller wheel will turn compared to the box when it turns once around the big one?

An ape is trying to climb on a pole that is 60 feet high. Due to the slippery surface, the ape climbs 3 feet in a minute only to slip back 2 feet.

How much time do you think the monkey will take to reach the top of the pole?

When is the top of a mountain similar to a savings account?