What word begins and ends with an E, but has only one letter?

John enters a small room. The Door Closes.
When the door opens, John is in a larger room.

Explain?

What is harder to catch the faster you run?

Why do we preferably have round manhole covers and not square ones?

See the given image carefully. What you have to do is move the blue checkers in the position of the black checkers and vice versa. You are only allowed to move the checker to an adjacent empty space. Do it in the least possible moves.

How many letters are in the alphabet?

You have a roll of cloth 1km long. You have a machine which cuts this roll into pieces of 10-meter-long cloth.

How long would it take for the machine to cut the roll if each cut took 4 secs?

10 people came into a hotel with 9 rooms and each guest wanted his own room. The bellboy solved this problem.
He asked the tenth guest to wait for a little with the first guest in room number 1. So in the first room, there were two people. The bellboy took the third guest to room number 2, the fourth to number 3, ..., and the ninth guest to room number 8. Then he returned to room number 1 and took the tenth guest to room number 9, still vacant.
How can everybody have his own room?

The more you take me, the more you leave me behind.
Who Am I?

Find the Next Number in the Sequence

2 9 3 1 8 4 3 6 5 7 ?