It has five wheels, though often think four, You cannot use it without that one more, You can put things in it, you can strap things on top, You can't find it in the market, but you can still go shop. What is it?

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?

If you go to the movies and you're paying, is it cheaper to take one friend to the movies twice, or two friends to the movies at the same time?

You can see three almost identical images below. Can you spot the odd one out from them?

Before Mount Everest was discovered, what was the highest mountain in the world?

I’m tall when I’m young, and I’m short when I’m old. What am I?

Can you identify the hidden rebus in the image below?

You have a 12 liters jug full of water. You have two empty 8 liters and 5 liters jug. How can you divide the water into two equal parts using these jugs?

I am the one who remains awake when you sleep. But I need to rest when you awake. Who Am I?

By removing one matchstick and adding one matchstick, can you convert the word "ZOO" to an animal name?