Name a key which is hardest to turn.

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

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

A man was gazing through the window of the 23rd floor of the building. He suddenly opened the window and jumped on the other side of the window. On landing on the floor, there was not a sheer mark of injury on him.

How can that be possible if he did not use any kind of parachute and did not land on a soft surface?

Bopanna was working on a murder case when he received a message about the location of the murder weapon.
The message was encrypted as below.

"deb mitciv eht edisni neddih si nopaew redrum ehT"

Tell me the location of the murder weapon.

A Shopkeeper sold a few chickens to four different customers on a particular day. It was such that each customer purchased half of the remaining chickens and half the chicken more.

Can you find out how many chicken were sold by the shopkeeper on that day if we tell you that the fourth customer bought a single chicken ?

What goes through cities and fields, but never moves?

Rearrange the letters in "new door" to make one word.

Can you name any English verb that becomes its past tense by simply rearranging the alphabets ?

Can you find out what is missing?

1 3 5
2 4 ?

Hint: It's not six. Think out of the box.