If it took eight men ten hours to build a wall, how long would it take four men to build it?

You see me once in June, twice in November, and not at all in May. What am I?

You are given a cube that is made with the help of 10x10x10 smaller cubes summing up to a total of 1000 smaller cubes. You are asked to take off one layer of the cubes.
How many remain now?

John was drowned by he was not wet. How?

Take away my first letter, then take away my second letter. Then take away the rest of my letters, yet I remain the same. What am I?

Who is that with a neck and no head, two arms and no hands? What is it?

What animal walks on four legs in the morning, two legs during the day, and three legs in the evening?

Oedipus, the king of Thebes, figured out the answer to the riddle:

A mile-long train is moving at sixty miles an hour when it reaches a mile-long tunnel. How long does it take the entire train to pass through the tunnel?

John was piloting a plane behind a car but was never able to overtake it. Why?

An exterior architect is asked by a builder to plant seven trees in a manner that there are exactly six rows of trees in a straight line and each row has three trees in particular.

How will he do it?