By removing one matchstick and adding one matchstick, can you convert the word "ZOO" to an animal name?

Rahul decided to meet Simran so he boards a local train from Bombay station. Just after the station, there is a 1km long tunnel. The train starts and is now accelerating. Rahul is a claustrophobic guy, so what is the best position for him to sit?

I am the fastest animal but cannot climb the tree. What am I?

4 fathers, 2 grand-fathers and 4 sons went to watch the movie.What is the minimum number of tickets they need to buy ?

Count the number of triangles in the picture below:

Can you convert the number zero(0) into a positive number using just one mathematical operator ?

There was a minor accident with a doctor's son but the doctor noticed no major injury. After the treatment, the father of that doctors son is sitting with the son of the doctor without the doctor being in the room.

How can this be possible?

John said, "If yesterday was tomorrow, today would be Friday."

When did John make this statement?

What is the fastest way to double your money?

What is black when you buy it, red when you use it, and gray when you throw it away?