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

One absent-minded ancient philosopher forgot to wind up his only clock in the house. He had no radio, TV, telephone, internet, or any other means for telling time. So he travelled on foot to his friend's place a few miles down the straight desert road. He stayed at his friend's house for the night and when he came back home, he knew how to set his clock. How did he know?

Nine marbles are arranged in the image below. Can you slide two marbles to form a square?

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

A boy was driving a car, a girl took a lift from her. She asked his name. The boy said - my name is hidden in my car’s number, find it if you can. After this, she got down Car number was [ WV733N ] Can you guess the name now?

What has lots of eyes, but can’t see?

Four men were in a boat on the lake. The boat turns over, and all four men sink to the bottom of the lake, yet not a single man got wet! Why?

How can you write nineteen in a manner that if we take out one, it becomes twenty?

How can you throw a ball as hard as you can and have it come back to you even if it doesn't hit anything there is nothing attached to it and no one else catches or throws it.

What is in seasons, seconds, centuries and minutes but not in decades, years or days?