Place a mathematical symbol between the numerals 5 and 9 in such a way that the resulting number is greater than 5 but smaller than 9.

I am a type of room you cannot enter or leave. Raised from the ground below, I could be poisonous or a delicious treat. What am I?

I have cities, but no houses. I have mountains, but no trees. I have water, but no fish. What am I?

There are 3 apples in the basket and you take away 2. How many apples do you have now?

What number do you get when you multiply all of the numbers on a telephone's number pad?

A man is trapped in a room. The room has only two possible exits doors. Through the first door there is a room constructed from magnifying glass. The blazing hot sun instantly fries anything or anyone that enters. Through the second door there is a fire-breathing dragon. How does the man escape?

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?

Count the number of triangles in the picture below:

How can a man go eight days without sleep?

John killed hundreds of people mercilessly and yet the police were not able to put her behind the bars. Why?