P is the father of Q and S is the son of R. T is the brother of P and has a daughter U. If R is the sister of P, then what is the relation between U, Q and S?

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 am a seven-letter word but if you remove four of my letters I will have one left. What word am I?

A guy in his thirties is found dead in a forest. The shocking thing about the body is that he is wearing his swimming trunks snorkel and a facemask.

For your information, the nearest lake is some 10 miles away and the sea is hundreds of miles away.

How did he die then?

I am the beginning of everything, the end of everywhere. I'm the beginning of eternity, the end of time and space. What am I?

2, 3, 5, 9, 17, _ What is the next number in the sequence?

There are people and strange monkeys on this island, and you can not tell who is who (Edit: until you understand what they said - see below). They speak either only the truth or only lies.
Who are the following two guys?
A: B is a lying monkey. I am human.
B: A is telling the truth.

What is always in front of you but can’t be seen?

You board a train. The train will have to enter a tunnel soon. You are claustrophobic. Which place is the best for you to sit?

You see a boat filled with people, yet there isn’t a single person on board. How is that possible?