What goes up but never comes down?

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?

People make me, save me, change me, raise me. What am I?

John is looking at Jenifer, but Jenifer is looking at Jacob. John is married, but Jacob is not.

Is a married person looking at an unmarried person ?

What do you call a fish without an eye?

You’ll find me on Mercury, Earth, Mars, Jupiter, Saturn, and Uranus. But never Neptune, or Venus. What am I?

In the given picture, in how many ways can you read the word "Tiger"?

Through your logical capabilities, can you make 7 an even?

Can you write down eight eights so that they add up to one thousand?

If all Goats are Sheep and all Sheep are Deers, are all Deers Goats ?