I travel all around the world but always stay in the corner. What am I?

There are four 3-link chains. All you have to do is join them into a big 12-link chain. For joining two closed links, one of the links must be cut and placed onto the other link for closing.

How many minimum links will you have to cut to make the big chain?

How many triangles can you count in the figure given?

I am a type of word that is spelt incorrectly or used differently, on purpose for humour. What am I?
Hint 1: You can find me in a joke.
Hint 2: I am a play on words.

A kind heart person buy packed food at 3$/packet from United states and sells them at 1$/packet at Africa. After some time he becomes a millionaire.

How come the guy become millionaire ?

Why 1729 is a magic number? Answer Logically.

You were playing ping pong with your friend. Suddenly the ball fell into a narrow metal pipe that was imbedded in the concrete surface of the floor one foot deep. Now you don't have any other ball and you desperately want to take it out and play. You and your friend have your shoelaces, your tennis paddle and a plastic water bottle. However, the bottle cannot fit into the pipe.

How will you take the ball out?

Can you identify the hidden rebus in the image below?

There is a brick of gold and a brick of iron in a boat (both 10-inch blocks), if they are both dropped into the water which will make the water level higher?

If we add four times the age of John four years from now to five times his age five years from now we get ten times his current age.

How old will John be two years from now?