You may enter, but you may not come in. I have space, but no room. I have keys, but open no lock. What am I?

Name a key which is hardest to turn.

How can a man go eight days without sleep?

If you say my name, I will no longer exist. What am I?

I am a five-letter word under you,
Remove the first letter and I am above you,
Remove the second as well and I am around you.

Who am I?

We have shown you a regular water barrel as below. Without using any measuring device can you check if the barrel is more than half-filled or less than half-filled?

A man is approaching a broad and barren land. He has a package with him. If somehow, he is unable to open the package before reaching the land, he will die.

Can you guess what is present in the package?

John replied, when asked how old he was. In 2 years he will be twice as old as he was five years ago.' How old is he ?

What will be the best approach to finding all the prime numbers less than 75 that leave an odd reminder when we divide them with 5?

A man is found dead with a knife in his back When the investigation is done. A chair lays beside him and the forensic team finds moisture around the body.

If he committed suicide, how did he do it?