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?

I look at you, you look at me I raise my right, you raise your left. What am I?

Nine marbles are arranged in the image below. Can you slide two marbles to form a square?

A bomb goes off.
Carnage.
One person, only a few feet away, survives! How can this be?

Can you find out what is missing?

1 3 5
2 4 ?

Hint: It's not six. Think out of the box.

In particular commonwealth games, a female participant won silver and gold medals for a single event.

How can this be possible?

We have four gears with below features=> Both Gear A and D has 60 teeth=> Gear B has 40 teeth=> Gear C has 20 teeth=> Every two minutes, Gear B makes 25 full turns.What is the relative speed of Gear A and Gear B?

Can you find the missing number in the third row?
35 20 14
27 12 18
5 2 ?

Three ants are sitting at the three corners of an equilateral triangle. Each ant starts randomly picks a direction and starts to move along the edge of the triangle. What is the probability that none of the ants collide?

Spelt forwards I’m what you do every day, spelled backwards I’m something you hate. What am I?