How can a man go eight days without sleep?

No matter how little or how much you use me, you change me every month. What am I?

On 26-01-2022, Juli was murdered at her house in a city in India in the afternoon. There were three suspects in the murder and the following are the statements that were given by them:

John: I visited my village that day.
Jacob: I was out to deposit my house tax in the municipality office at that time.
Jonny: I was at a friend's place having lunch at that time.

Can you find out who is the murderer?

John went to meet his friend Jacob, but when he was about to reach the main gate, John notices that Jacob had a mighty dog who was fastened to the tree. The chain is long enough that it allows the dog to reach the main gate.

How can the John reach the main gate?

A dead body is found outside a multi-story multinational company. The case is reported and a homicide detective is called on the crime scene.

He looks at the body and then towards the building. From the position of the body, it is evident that the victim committed suicide. He goes to the first floor of the building and then walks in the direction of the dead body, opens the window and toss a coin in the air.

He goes to second floor and again repeats the process. He keeps doing this till he is done on all the floors. Then he returns back to the floor and tells his team that it is a murder.

How in heaven did he deduce that?

What can you serve, but never eat?

You are playing as white and given four rooks to checkmate the black king in four moves with the following rules 1. You can place one rook every move and ensure the black king should be in check position.2. After four moves the black king should be in the checkmate position.

Your job is to measure 45 minutes if you have only two cords and matches to light the cords.

1. The two cords are twisted from various materials, so their different segments can burn at different rates.
2. Each cord burns from end to end in exactly one hour.

Describe your way of measuring the 45 minutes.

What is the largest number you can write with just 3 digits?

How many words can a pen with half refill write?