Name a key which is hardest to turn.

There are two candles. Both will only burn exactly for an hour. How will you use these two candles to measure forty-five minutes?

You need to move three matchsticks to form three squares. Can you do it?

100 prisoners are stuck in the prison in solitary cells. The warden of the prison got bored one day and offered them a challenge. He will put one prisoner per day, selected at random (a prisoner can be selected more than once), into a special room with a light bulb and a switch which controls the bulb. No other prisoners can see or control the light bulb. The prisoner in the special room can either turn on the bulb, turn off the bulb or do nothing. On any day, the prisoners can stop this process and say "Every prisoner has been in the special room at least once". If that happens to be true, all the prisoners will be set free. If it is false, then all the prisoners will be executed. The prisoners are given some time to discuss and figure out a solution. How do they ensure they all go free?

What have one eye but still cannot see?

Why blonde cannot dial 911?

How many times do a clock's hands overlap in a day ?

John went to a parrot shop in Mexico, and the parrot owner told him that his parrot is so unique that he repeats everything he hears. John got excited and immediately bought the parrot. John went home and spoke many words, but the parrot does not repeat anything.
He went again to the parrot shop and complaint to the shopkeeper, but the shopkeeper never lied. Explain?

Imagine you are in a room with no windows or doors. How will you get out?

You can see it everyday, But cannot touch it at will. What is it?