What number when divided in half becomes zero?

What always comes into a house through the keyhole?

It's a protector.
It sits on a bridge.
One individual can see directly through it, while others wonder what it hides.

What is it?

Decode this picture on T-Shirt and tell what it says ?

A man has a barrel filled with oil that weighs 100 pounds, and then he puts something into it. Now the barrel weighs less than 100 pounds. What did he put in the barrel?

The barber of Town shaves all men living in the town. No man living in the town is allowed to shave himself. The barber lives in that town. Who then shaves the barber of the town?

A bomb exploded in a room full of married couples and no one died. How?

How many words can a pen with half refill write?

A man was driving a black truck. His lights were not on. The moon was not out. A lady was crossing the street. How did the man see her?

What is red and smells like blue paint?