What always comes into a house through the keyhole?

How is a fly different from a mosquito?

Can you solve this tricky maths equation problem by replacing it? mark with the correct symbol?

19834 -----: 187
15921 -----: 153
17561 -----: 139
13734 -----: ???

The barber of Town shaves all men living in the town. No man living in the town is allowed to shave himself. The barber lives in that town. Who then shaves the barber of the town?

Can it be possible to build a house that has all its four walls facing towards the South?

If you toss a coin 10 times and it lands heads up every time, what are the chances it will land heads up if you toss it again?

Can you place six X (crosses) in below board without making three in a row in any way ?

How can a man go eight days without sleep?

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 is black when you buy it, red when you use it, and gray when you throw it away?