If I remove one from eleven it becomes Ten and if I remove one from nine also becomes Ten. How?

What goes up but never comes down?

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

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?

How is a fly different from a mosquito?

My location can be determined by the below rebus.
So where am i ?

Can you convert the number zero(0) into a positive number using just one mathematical operator ?

I am lying and I always lie. Tell me whether I am lying or telling the truth.

We can be boring,Or interesting.
We can be long,Or short.
We can have pictures,Or just words.
Many love us,But many also hate us.
What are we?

If in a car race, the man who came two places in front of the last man finished one ahead of the man who came fifth, how many contestants were there?