What has many keys but can’t open a single lock?

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?

This puzzle is for Harry Potter fans. Do you know why Tom Riddle is called Lord Voldemort?

If you remove one from eleven, it becomes ten. If you remove one from nine, it becomes ten.

How is this possible?

I have a hole in my back and legs I lack.
I live where I can’t breathe and I eat without teeth.
What am I?

What is the difference between a jeweller and a jailer?

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

What seven-letter word has hundreds of letters in it?

A certain street contains 100 buildings. They are numbered from 1 to 100. How many 9's are used in these numbers?

What does below chemistry rebus means?