If there are fifteen crows on a fence and the farmer shoots a third of them, how many crows are left?

A patient was diagnosed with some ailment. He was given five different tablets to take at night at an interval of 15 minutes.

How long will it take the patient to consume all the five tablets?

You can see it everyday, But cannot touch it at will. What is it?

When I got four, I have it none.
When I got two, I have it some.
When I got none, I have it all.

What is it?

By using 'because' continuously three times, can you make an English statement ?

A bus driver was heading down a street in Mexico. He went right past a stop sign without stopping, he turned left where there was a "no left turn" sign, and he went the wrong way on a one-way street. Then he went on the left side of the road past a cop car. Still - he didn't break any traffic laws. Why not?

I am not alive, but I grow; I don't have lungs, but I need air; I don't have a mouth, but water kills me. What am I?

What 4-letter word can be written forward, backward or upside down, and can still be read from left to right?

What is so fragile that saying its name breaks it?

What can you catch but never throw?