Best riddles

I build up castles. I tear down mountains. I make some men blind, I help others to see. What am I?

Farmer Brown came to town with some watermelons. He sold half of them plus half a melon and found that he had one whole melon left. How many melons did he take to town?

What do you get when you drop a pumpkin?

I create my lair with earthen string and dispatch my prey with a biting sting. What am I?

What has no beginning, end, or middle?

A man was driving a truck at 60 mph. He did not have his headlights on and the moon was not up. Yet he did not hit the woman who crossed the road. How?

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

There is a low railroad bridge in your town. One day you see a large truck stopped just before the underpass. When you ask what has happened, the driver tells you that his truck is one inch higher than the indicated height of the opening. This is the only road to his destination. What can he do to get through the underpass the easiest way?

What is it that you throw away the outer side, then cook the insides and then throw away the insides – what is the name of the item?

Find three positive whole numbers that have the same answer added together or when multiplied together.